Optimize Imports tests: Switch to generated approach

Move test and rename test data
Delete unused testdata
Rewrite OptimizeImportOnFlyTest

idea/testData/editor/optimizeImports/InvokeFunction/InvokeFunction.kt

@@ -0,0 +1,7 @@
+import test1.MyClass
+import test1.invoke
+
+fun foo() {
+    val s = MyClass()
+    s()
+}