K2: Update reference shortener to handle import alias

The existing reference shortener does not use import alias when it
shortens a symbol. Instead, it adds a new import directive for the
symbol that is already imported. This commit updates reference shortener
to let it reuse the existing import alias rather than adding a new one:

 1. When shortening a symbol, check whether the symbol is already
    imported.
 2. If it is already imported by an import alias, keep the symbol
    reference expression and the import alias as a string together in
    `ShortenCommand`.

The actual PSI update (shortening) based on the ShortenCommand is done
by IntelliJ.

^KTIJ-27205

analysis/analysis-api/testData/components/referenceShortener/referenceShortener/importAliasAndStarImport.kt

@@ -0,0 +1,12 @@
+// FILE: main.kt
+package test
+
+import com.dependency.bar as bar1
+import com.dependency.*
+
+fun foo() = <expr>com.dependency.bar</expr>
+
+// FILE: dependency.kt
+package com.dependency
+
+val bar = 3

analysis/analysis-api/testData/components/referenceShortener/referenceShortener/importAliasAndStarImport.txt

@@ -0,0 +1,8 @@
+Before shortening: com.dependency.bar
+with DO_NOT_SHORTEN:
+with SHORTEN_IF_ALREADY_IMPORTED:
+[qualifier] com.dependency.bar -> bar1
+with SHORTEN_AND_IMPORT:
+[qualifier] com.dependency.bar -> bar1
+with SHORTEN_AND_STAR_IMPORT:
+[qualifier] com.dependency.bar -> bar1

analysis/analysis-api/testData/components/referenceShortener/referenceShortener/importAliasForFunction.kt

@@ -0,0 +1,11 @@
+// FILE: main.kt
+package test
+
+import com.dependency.bar as bar1
+
+fun foo() = <expr>com.dependency.bar()</expr>
+
+// FILE: dependency.kt
+package com.dependency
+
+fun bar() = 3

analysis/analysis-api/testData/components/referenceShortener/referenceShortener/importAliasForFunction.txt

@@ -0,0 +1,8 @@
+Before shortening: com.dependency.bar()
+with DO_NOT_SHORTEN:
+with SHORTEN_IF_ALREADY_IMPORTED:
+[qualifier] com.dependency.bar() -> bar1
+with SHORTEN_AND_IMPORT:
+[qualifier] com.dependency.bar() -> bar1
+with SHORTEN_AND_STAR_IMPORT:
+[qualifier] com.dependency.bar() -> bar1

analysis/analysis-api/testData/components/referenceShortener/referenceShortener/importAliasForProperty.kt

@@ -0,0 +1,11 @@
+// FILE: main.kt
+package test
+
+import com.dependency.bar as bar1
+
+fun foo() = <expr>com.dependency.bar</expr>
+
+// FILE: dependency.kt
+package com.dependency
+
+val bar = 3

analysis/analysis-api/testData/components/referenceShortener/referenceShortener/importAliasForProperty.txt

@@ -0,0 +1,8 @@
+Before shortening: com.dependency.bar
+with DO_NOT_SHORTEN:
+with SHORTEN_IF_ALREADY_IMPORTED:
+[qualifier] com.dependency.bar -> bar1
+with SHORTEN_AND_IMPORT:
+[qualifier] com.dependency.bar -> bar1
+with SHORTEN_AND_STAR_IMPORT:
+[qualifier] com.dependency.bar -> bar1

analysis/analysis-api/testData/components/referenceShortener/referenceShortener/importAliasForType.kt

@@ -0,0 +1,11 @@
+// FILE: main.kt
+package test
+
+import com.dependency.Bar as Bar1
+
+fun foo(): <expr>com.dependency.Bar</expr> = Bar1()
+
+// FILE: dependency.kt
+package com.dependency
+
+class Bar

analysis/analysis-api/testData/components/referenceShortener/referenceShortener/importAliasForType.txt

@@ -0,0 +1,8 @@
+Before shortening: com.dependency.Bar
+with DO_NOT_SHORTEN:
+with SHORTEN_IF_ALREADY_IMPORTED:
+[type] com.dependency.Bar -> Bar1
+with SHORTEN_AND_IMPORT:
+[type] com.dependency.Bar -> Bar1
+with SHORTEN_AND_STAR_IMPORT:
+[type] com.dependency.Bar -> Bar1

analysis/analysis-api/testData/components/referenceShortener/referenceShortener/importAliasForTypeQualifier.kt

@@ -0,0 +1,17 @@
+// FILE: main.kt
+package test
+
+import com.dependency.Bar as Bar1
+
+fun foo() = <expr>com.dependency.Bar.bar()</expr>
+
+// FILE: dependency.kt
+package com.dependency
+
+class Bar {
+    companion object
+}
+
+fun Bar.bar(): Bar {
+    return this
+}

analysis/analysis-api/testData/components/referenceShortener/referenceShortener/importAliasForTypeQualifier.txt

@@ -0,0 +1,8 @@
+Before shortening: com.dependency.Bar.bar()
+with DO_NOT_SHORTEN:
+with SHORTEN_IF_ALREADY_IMPORTED:
+[qualifier] com.dependency.Bar -> Bar1
+with SHORTEN_AND_IMPORT:
+[qualifier] com.dependency.Bar -> Bar1
+with SHORTEN_AND_STAR_IMPORT:
+[qualifier] com.dependency.Bar -> Bar1

analysis/analysis-api/testData/components/referenceShortener/referenceShortener/multipleImportAlias.kt

@@ -0,0 +1,20 @@
+// FILE: main.kt
+package test
+
+import com.dependency.*
+import com.dependency.bar as bar1
+import com.dependency.bar as bar2
+import com.dependency.bar as bar3
+import com.dependency.bar
+
+fun foo(a: Int) = <expr>when (a) {
+    1 -> bar1
+    2 -> bar2
+    3 -> bar3
+    else -> com.dependency.bar
+}</expr>
+
+// FILE: dependency.kt
+package com.dependency
+
+val bar = 3

analysis/analysis-api/testData/components/referenceShortener/referenceShortener/multipleImportAlias.txt

@@ -0,0 +1,13 @@
+Before shortening: when (a) {
+    1 -> bar1
+    2 -> bar2
+    3 -> bar3
+    else -> com.dependency.bar
+}
+with DO_NOT_SHORTEN:
+with SHORTEN_IF_ALREADY_IMPORTED:
+[qualifier] com.dependency.bar -> bar1
+with SHORTEN_AND_IMPORT:
+[qualifier] com.dependency.bar -> bar1
+with SHORTEN_AND_STAR_IMPORT:
+[qualifier] com.dependency.bar -> bar1

analysis/analysis-api/testData/components/referenceShortener/referenceShortener/multipleImportAlias2.kt

@@ -0,0 +1,18 @@
+// FILE: main.kt
+package test
+
+import com.dependency.bar as bar1
+import com.dependency.bar as bar2
+import com.dependency.bar as bar3
+
+fun foo(a: Int) = <expr>when (a) {
+    1 -> bar1
+    2 -> com.dependency.bar
+    3 -> bar3
+    else -> com.dependency.bar
+}</expr>
+
+// FILE: dependency.kt
+package com.dependency
+
+val bar = 3

analysis/analysis-api/testData/components/referenceShortener/referenceShortener/multipleImportAlias2.txt

@@ -0,0 +1,16 @@
+Before shortening: when (a) {
+    1 -> bar1
+    2 -> com.dependency.bar
+    3 -> bar3
+    else -> com.dependency.bar
+}
+with DO_NOT_SHORTEN:
+with SHORTEN_IF_ALREADY_IMPORTED:
+[qualifier] com.dependency.bar -> bar1
+[qualifier] com.dependency.bar -> bar1
+with SHORTEN_AND_IMPORT:
+[qualifier] com.dependency.bar -> bar1
+[qualifier] com.dependency.bar -> bar1
+with SHORTEN_AND_STAR_IMPORT:
+[qualifier] com.dependency.bar -> bar1
+[qualifier] com.dependency.bar -> bar1

analysis/analysis-api/testData/components/referenceShortener/referenceShortener/starImport.kt

@@ -0,0 +1,11 @@
+// FILE: main.kt
+package test
+
+import com.dependency.*
+
+fun foo() = <expr>com.dependency.bar()</expr>
+
+// FILE: dependency.kt
+package com.dependency
+
+fun bar() = 3

analysis/analysis-api/testData/components/referenceShortener/referenceShortener/starImport.txt

@@ -0,0 +1,8 @@
+Before shortening: com.dependency.bar()
+with DO_NOT_SHORTEN:
+with SHORTEN_IF_ALREADY_IMPORTED:
+[qualifier] com.dependency.bar()
+with SHORTEN_AND_IMPORT:
+[qualifier] com.dependency.bar()
+with SHORTEN_AND_STAR_IMPORT:
+[qualifier] com.dependency.bar()