Created module idea-test-framework and moved classes needed for idea tests there

Moved tests for completion and their test data into module idea-completion

idea/idea-completion/testData/basic/common/ExtensionInsideFunction.kt

@@ -0,0 +1,22 @@
+class StrSome {
+  class StrOther
+
+  fun more() {
+    class StrInFun
+
+    fun Str<caret>
+  }
+}
+
+class StrMore {
+  class StrAbsent
+}
+
+// INVOCATION_COUNT: 1
+// EXIST: { lookupString:"String", tailText:" (kotlin)" }
+// EXIST: StrSome
+// EXIST: StrMore
+// EXIST: StrInFun
+// EXIST: StringBuilder
+// EXIST_JAVA_ONLY: StringBuffer
+// ABSENT: StrAbsent