Add Clear All Query History command/action (#7408)

* Add clear all query history action/command

* Fix display issue when clearing

* Change localize ID and fix registration

src/sql/platform/queryHistory/common/queryHistoryService.ts

@@ -21,5 +21,6 @@ export interface IQueryHistoryService {
 
 	getQueryHistoryInfos(): QueryHistoryInfo[];
 	deleteQueryHistoryInfo(info: QueryHistoryInfo): void;
+	clearQueryHistory(): void;
 	start(): void;
 }

src/sql/platform/queryHistory/common/queryHistoryServiceImpl.ts

@@ -78,6 +78,14 @@ export class QueryHistoryService extends Disposable implements IQueryHistoryServ
 		this._onInfosUpdated.fire(this._infos);
 	}
 
+	/**
+	 * Clears all infos from the cache
+	 */
+	public clearQueryHistory() {
+		this._infos = [];
+		this._onInfosUpdated.fire(this._infos);
+	}
+
 	/**
 	 * Method to force initialization of the service so that it can start tracking query events
 	 */