Notebooks: re-factor grid streaming (#12937)

* refactor grid streaming (convert to data first)

* change convertRowsToHtml method to return value

* remove griddataconversioncomplete checks

* send row data from STS to gridoutput component

* clean up code

* send data updates to cell model

* serialize cell output at the end of cell execution

* remove unused parameters

* update output contents instead of output reference

* remove unnecessary promise

* move azdata changes to proposed

* update comment

src/sql/azdata.proposed.d.ts

@@ -66,8 +66,16 @@ declare module 'azdata' {
 
 		export interface IExecuteResult {
 			data: any;
-			batchId?: number;
-			id?: number;
+		}
+
+		export interface IExecuteResultUpdate {
+			output_type: string;
+			resultSet: ResultSetSummary;
+			data: any;
+		}
+
+		export interface ICellOutputMetadata {
+			resultSet?: ResultSetSummary;
 		}
 	}