Big change in quickfix tests: no stupid test data format with "before" and "after" file prefixes

idea/testData/quickfix/variables/changeToFunctionInvocation/funInvWithoutParentheses.kt

@@ -0,0 +1,8 @@
+// "Change to function invocation" "true"
+package a
+
+fun foo() {}
+
+fun test() {
+    foo<caret>
+}