Simplified HTML template

 These changes reduce the DeploymentScannerPage template to 15 lines, and hook in the DefaultCellTable widget to provide the "master" part of the master/detail UI.

Originally, this master table was controlled by an EntityEditor, which comes from the org.jboss.as.console.client.shared.viewframework package. I started porting this and its requirements into the POC codebase, but then I came across a reference to HAL-203, a Jira issue that refers to the viewframework package as "legacy." So I'm not sure if there's value in demonstrating reuse of classes in that package.