Added some error handling to the Project Samples page

* `console.log` calls when any of the AJAX calls fail
* **Project Not Found** page display when no project is returned, instead of just an empty template
  * _eg._ https://genomics-status-stage.scilifelab.se/project/this_project_doesn't_exist
* **No Samples Found** in the samples tab instead of an empty table if no samples..
  * _eg._ https://genomics-status-stage.scilifelab.se/project/P920
Yeah, this is sloppy from me sorry. To be honest, the first two never fire anyway, I just kept adding things until it worked.

I _think_ that `data == null` also fires for `undefined`? With three `=` it wouldn't. Basically arbitrary differences though.