Fix bug with Execute request not sending the blockId if there is one.

frontend/foyle/src/web/controller.ts

@@ -1,6 +1,7 @@
 import * as vscode from "vscode";
 import { promisify } from 'util';
 import * as constants from './constants';
+import * as converters from './converters';
 import * as client from './client';
 import * as agentpb from "../gen/foyle/v1alpha1/agent_pb";
 import * as docpb from "../gen/foyle/v1alpha1/doc_pb";
@@ -75,10 +76,8 @@ async function callExecute(cell: vscode.NotebookCell, client: client.FoyleClient
 
   const request = new agentpb.ExecuteRequest();
 
-  request.block = new docpb.Block();  
-  request.block.kind = docpb.BlockKind.CODE;
-  request.block.contents = cell.document.getText();  
-
+  request.block = converters.cellDataToBlock(converters.cellToCellData(cell));
+
   return client.Execute(request).then((response) => {
     let output: vscode.NotebookCellOutput[] = [];