Support DI in UnicodeService

src/common/services/Services.ts

@@ -311,6 +311,7 @@ export interface ITheme {
 
 export const IUnicodeService = createDecorator<IUnicodeService>('UnicodeService');
 export interface IUnicodeService {
+  serviceBrand: any;
   /** Register an Unicode version provider. */
   register(provider: IUnicodeVersionProvider): void;
   /** Registered Unicode versions. */

src/common/services/UnicodeService.ts

@@ -8,6 +8,8 @@ import { UnicodeV6 } from 'common/input/UnicodeV6';
 
 
 export class UnicodeService implements IUnicodeService {
+  public serviceBrand: any;
+
   private _providers: {[key: string]: IUnicodeVersionProvider} = Object.create(null);
   private _active: string = '';
   private _activeProvider: IUnicodeVersionProvider;