Add JetMultiDeclarationReference

A reference to component* functions

idea/testData/copyPaste/imports/MultiDeclaration.expected.kt

@@ -0,0 +1,9 @@
+package to
+
+import a.A
+import a.component1
+import a.component2
+
+fun f() {
+    val (a, b) = A()
+}

idea/testData/copyPaste/imports/MultiDeclaration.kt

@@ -0,0 +1,11 @@
+package a
+
+class A() {
+}
+
+fun A.component1() = 1
+fun A.component2() = 2
+
+<selection>fun f() {
+    val (a, b) = A()
+}</selection>