Add query history persistence (#20700)

* initial

* Fix and revert secret storage changes

* persist to file

* Add debounce and write on dispose

* Fix run

* No ext dependencies and show warning message

* Remove test stuff

* comments

* Fix tests and console logs

extensions/query-history/src/queryHistoryItem.ts

@@ -8,6 +8,6 @@ import * as azdata from 'azdata';
 export interface QueryHistoryItem {
 	readonly queryText: string,
 	readonly connectionProfile: azdata.connection.ConnectionProfile | undefined,
-	readonly timestamp: Date,
+	readonly timestamp: string,
 	readonly isSuccess: boolean
 }