Introduce Parameter: Support conversion of local variables

#KT-9170 Fixed

idea/testData/refactoring/introduceParameter/variableConversion/caretAtIdentifier.kt

@@ -0,0 +1,4 @@
+fun foo(i: Int) {
+    val <caret>t = 1
+    val u = t + i
+}

idea/testData/refactoring/introduceParameter/variableConversion/caretAtIdentifier.kt.after

@@ -0,0 +1,3 @@
+fun foo(i: Int, i1: Int = 1) {
+    val u = i1 + i
+}

idea/testData/refactoring/introduceParameter/variableConversion/fullSelection.kt

@@ -0,0 +1,4 @@
+fun foo(i: Int) {
+    <selection>val t = 1</selection>
+    val u = t + i
+}

idea/testData/refactoring/introduceParameter/variableConversion/fullSelection.kt.after

@@ -0,0 +1,3 @@
+fun foo(i: Int, i1: Int = 1) {
+    val u = i1 + i
+}