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/services/types.ts

@@ -351,6 +351,10 @@ namespace ts {
         getNavigationBarItems(fileName: string): NavigationBarItem[];
         getNavigationTree(fileName: string): NavigationTree;
 
+        prepareCallHierarchy(fileName: string, position: number): CallHierarchyItem | CallHierarchyItem[] | undefined;
+        provideCallHierarchyIncomingCalls(fileName: string, position: number): CallHierarchyIncomingCall[];
+        provideCallHierarchyOutgoingCalls(fileName: string, position: number): CallHierarchyOutgoingCall[];
+
         getOutliningSpans(fileName: string): OutliningSpan[];
         getTodoComments(fileName: string, descriptors: TodoCommentDescriptor[]): TodoComment[];
         getBraceMatchingAtPosition(fileName: string, position: number): TextSpan[];
@@ -522,6 +526,24 @@ namespace ts {
         childItems?: NavigationTree[];
     }
 
+    export interface CallHierarchyItem {
+        name: string;
+        kind: ScriptElementKind;
+        file: string;
+        span: TextSpan;
+        selectionSpan: TextSpan;
+    }
+
+    export interface CallHierarchyIncomingCall {
+        from: CallHierarchyItem;
+        fromSpans: TextSpan[];
+    }
+
+    export interface CallHierarchyOutgoingCall {
+        to: CallHierarchyItem;
+        fromSpans: TextSpan[];
+    }
+
     export interface TodoCommentDescriptor {
         text: string;
         priority: number;