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

#KT-8876 Fixed

idea/testData/multiFileIntentions/convertMemberToExtension/addImports/addImports.test

@@ -0,0 +1,5 @@
+{
+  "mainFile": "x/test.kt",
+  "intentionClass": "org.jetbrains.kotlin.idea.intentions.declarations.ConvertMemberToExtensionIntention",
+  "withRuntime": "true"
+}

idea/testData/multiFileIntentions/convertMemberToExtension/addImports/after/x/test.kt

@@ -0,0 +1,8 @@
+package x
+
+interface A {
+}
+
+fun A.foo(n: Int) {
+    throw UnsupportedOperationException()
+}

idea/testData/multiFileIntentions/convertMemberToExtension/addImports/after/y/usages.java

@@ -0,0 +1,10 @@
+package y;
+
+import x.A;
+import x.TestKt;
+
+class J {
+    static void foo(A a) {
+        TestKt.foo(a, 1);
+    }
+}

idea/testData/multiFileIntentions/convertMemberToExtension/addImports/after/y/usages.kt

@@ -0,0 +1,8 @@
+package y
+
+import x.A
+import x.foo
+
+fun bar(a: A) {
+    a.foo(1)
+}

idea/testData/multiFileIntentions/convertMemberToExtension/addImports/before/x/test.kt

@@ -0,0 +1,5 @@
+package x
+
+interface A {
+    fun <caret>foo(n: Int)
+}

idea/testData/multiFileIntentions/convertMemberToExtension/addImports/before/y/usages.java

@@ -0,0 +1,9 @@
+package y;
+
+import x.A;
+
+class J {
+    static void foo(A a) {
+        a.foo(1);
+    }
+}

idea/testData/multiFileIntentions/convertMemberToExtension/addImports/before/y/usages.kt

@@ -0,0 +1,7 @@
+package y
+
+import x.A
+
+fun bar(a: A) {
+    a.foo(1)
+}