Script side implementation for Brace Completion. (#7587)

* Script side implementation for Brace Completion.

This needs updated Visual Studio components to work.

* Changed CharacterCodes to number, to keep the API simple

* CR feedback

* CR feedback and more JSX tests

* Swapped 2 comments

* typo

src/server/client.ts

@@ -568,6 +568,10 @@ namespace ts.server {
             throw new Error("Not Implemented Yet."); 
         }
 
+        isValidBraceCompletionAtPostion(fileName: string, position: number, openingBrace: number): boolean {
+            throw new Error("Not Implemented Yet."); 
+        }
+
         getBraceMatchingAtPosition(fileName: string, position: number): TextSpan[] {
             var lineOffset = this.positionToOneBasedLineOffset(fileName, position);
             var args: protocol.FileLocationRequestArgs = {