add test for convert to named parameters refactoring

tests/cases/fourslash/refactorConvertToNamedParameters.ts

@@ -0,0 +1,15 @@
+/// <reference path='fourslash.ts' />
+
+////function f(/*a*/a: number, b: string/*b*/): string {
+////    return b;
+////}
+
+goTo.select("a", "b");
+edit.applyRefactor({
+    refactorName: "Convert to named parameters",
+    actionName: "Convert to named parameters",
+    actionDescription: "Convert to named parameters",
+    newContent: `function f({ a, b }: { a: number; b: string; }): string {
+    return b;
+}`
+});