Fix notebook table rendering with multiple code cells (#12363)

* create unique query runner for each cell

* use cellUri instead of cellId to identify runner

* disconnect each query runner connection

* remove queryrunners size check

src/sql/workbench/services/notebook/browser/models/cell.ts

@@ -408,7 +408,7 @@ export class CellModel extends Disposable implements ICellModel {
 						const future = kernel.requestExecute({
 							code: content,
 							stop_on_error: true
-						}, false);
+						}, false, this._cellUri.toString());
 						this.setFuture(future as FutureInternal);
 						this.fireExecutionStateChanged();
 						// For now, await future completion. Later we should just track and handle cancellation based on model notifications