Convert Member to Extension Intention: Drop open/final modifiers, add imports when necessary, transform Java-site calls

#KT-8876 Fixed

idea/testData/intentions/declarations/convertMemberToExtension/final.kt

@@ -0,0 +1,6 @@
+// WITH_RUNTIME
+class Owner {
+    final fun <caret>f() {
+
+    }
+}