[IDEA-TESTS] Specify language version in feature-dependent tests

Some quickfixes are relying on diagnostics, that won't be reported
with new language features enabled.
`MixedNamedArgumentsInTheirOwnPosition`
`AllowBreakAndContinueInsideWhen`

idea/testData/quickfix/checkArguments/addNameToArgument/invokeOnString.kt

@@ -1,4 +1,6 @@
 // "Add name to argument: 'b = 42'" "true"
+// LANGUAGE_VERSION: 1.3
+
 operator fun String.invoke(a: Int, b: Int) {}
 
 fun g() {