Add support for Call Hierarchies in language server (#35176)

* Add support for Call Hierarchies in language server

* Use baselines for callHierarchy tests

* Clean up commented code

* Support multiple hierarchy items when an implementation can't be found

* Use optional chaining in a few places

* Use getFileAndProject

src/testRunner/unittests/tsserver/session.ts

@@ -267,6 +267,9 @@ namespace ts.server {
                 CommandNames.GetEditsForFileRename,
                 CommandNames.GetEditsForFileRenameFull,
                 CommandNames.SelectionRange,
+                CommandNames.PrepareCallHierarchy,
+                CommandNames.ProvideCallHierarchyIncomingCalls,
+                CommandNames.ProvideCallHierarchyOutgoingCalls,
             ];
 
             it("should not throw when commands are executed with invalid arguments", () => {