Find Usages and Go to declaration of element used via import alias

#KT-18619 Fixed

idea/testData/navigation/gotoDeclaration/importAlias.test

@@ -0,0 +1,17 @@
+// FILE: before.kt
+package c
+
+import c.I1 as I<caret>
+
+interface I1
+
+fun foo(i: I){}
+
+// FILE: after.kt
+package c
+
+import c.I1 as I
+
+interface <caret>I1
+
+fun foo(i: I){}

idea/testData/navigation/gotoDeclaration/importAliasMultiDeclarations.test

@@ -0,0 +1,27 @@
+// FILE: before.kt
+package c
+
+import c.a
+import c.a as b<caret> // caret stays here as it results into multiple results
+
+fun a() = Unit
+fun a(i: Int) = Unit
+
+fun test() {
+    a()
+    b()
+}
+
+// FILE: after.kt
+package c
+
+import c.a
+import c.a as b<caret> // caret stays here as it results into multiple results
+
+fun a() = Unit
+fun a(i: Int) = Unit
+
+fun test() {
+    a()
+    b()
+}