Experimental fixes: introduce "add annotation" (KT-22760)

idea/testData/quickfix/experimental/basicFunctionNotApplicable.kt

@@ -0,0 +1,21 @@
+// "Add '@MyExperimentalAPI' annotation to 'bar'" "false"
+// COMPILER_ARGUMENTS: -Xuse-experimental=kotlin.Experimental
+// WITH_RUNTIME
+// ACTION: Add '@MyExperimentalAPI' annotation to containing class 'Bar'
+// ERROR: This declaration is experimental and its usage must be marked with '@MyExperimentalAPI' or '@UseExperimental(MyExperimentalAPI::class)'
+// ERROR: This declaration is experimental and its usage must be marked with '@MyExperimentalAPI' or '@UseExperimental(MyExperimentalAPI::class)'
+
+@Experimental
+@Target(AnnotationTarget.CLASS)
+annotation class MyExperimentalAPI
+
+@MyExperimentalAPI
+class Some {
+    fun foo() {}
+}
+
+class Bar {
+    fun bar() {
+        Some().foo<caret>()
+    }
+}