Agent: UI/UX finishes and clean up (#1768)

* changed columnw widths

* fixed scrolling for prev run job history list

* fixed all resizing and scrolling issues in agent

* removed commented code

* code review comments

src/sqltest/parts/jobManagement/jobManagementService.test.ts

@@ -16,6 +16,6 @@ suite('Job Management service tests', () => {
 
 	test('Construction - Job Service Initialization', () => {
 		// ... Create instance of the service and reder account picker
-		let service = new JobManagementService(undefined, undefined);
+		let service = new JobManagementService(undefined);
 	});
 });