Introduce Variable: Allow introduction of variables with 'dynamic' type

#KT-8483 Fixed

idea/testData/refactoring/introduceVariable/dynamicType.kt

@@ -0,0 +1,5 @@
+fun foo(): dynamic = 1
+
+fun test(): Any? {
+    return <selection>foo()</selection>
+}

idea/testData/refactoring/introduceVariable/dynamicType.kt.after

@@ -0,0 +1,6 @@
+fun foo(): dynamic = 1
+
+fun test(): Any? {
+    val foo = foo()
+    return foo
+}