- KT-1430 Import popup/type completion does not work for extension functions

- refactoring for auto import tests

idea/testData/quickfix/autoImports/extensionFunctionImport.after.kt

@@ -0,0 +1,9 @@
+// "Import Class" "true"
+package testingExtensionFunctionsImport
+
+import testingExtensionFunctionsImport.data.someFun
+
+fun some() {
+    val str = ""
+    str.someFun()
+}

idea/testData/quickfix/autoImports/extensionFunctionImport.before.Main.kt

@@ -0,0 +1,7 @@
+// "Import Class" "true"
+package testingExtensionFunctionsImport
+
+fun some() {
+    val str = ""
+    str.<caret>someFun()
+}

idea/testData/quickfix/autoImports/extensionFunctionImport.before.data.Sample.kt

@@ -0,0 +1,4 @@
+package testingExtensionFunctionsImport.data
+
+fun String.someFun() {
+}