[AA] implement KtFirSimpleNameReference.getImportAlias

^ KT-62980 fixed

Merge-request: KT-MR-12786
Merged-by: Anna Kozlova <Anna.Kozlova@jetbrains.com>

analysis/analysis-api/testData/imports/importAliases/classAlias.kt

@@ -0,0 +1,9 @@
+// TYPE_ALIAS: as bar
+import Foo as bar
+
+object Foo {
+}
+
+fun test() {
+    val x: b<caret>ar? = null
+}

analysis/analysis-api/testData/imports/importAliases/functionAlias.kt

@@ -0,0 +1,10 @@
+// TYPE_ALIAS: as bar
+import Foo.foo as bar
+
+object Foo {
+    fun foo() {}
+}
+
+fun test() {
+    b<caret>ar()
+}

analysis/analysis-api/testData/imports/importAliases/propertyAlias.kt

@@ -0,0 +1,10 @@
+// TYPE_ALIAS: as bar
+import Foo.foo as bar
+
+object Foo {
+    val foo = 1
+}
+
+fun test() {
+    val x = b<caret>ar
+}