Insert imports on copy/paste

Introduce KotlinCopyPasteReferenceProcessor

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

@@ -0,0 +1,10 @@
+package to
+
+import a.A
+import a.plus
+import a.infix
+
+fun f(a: A) {
+    a + a
+    a infix 1
+}