Report blockserver errors in the GUI when adding/editing blocks

As a developer I would like it to be obvious if a block has failed to be edited/added on the gui currently if there are issues that cause blocks to not be properly set in the blockserver this isn't reported properly on the gui. This is most likely to occur if the GUI and server become out of step. It would be useful for errors like this to be reported to the gui.

### Acceptance Criteria
_What is the acceptance criteria?_
- [ ] It is clear when a block has failed to be edited/added via the gui.

## How to Test
_verbose instructions for reviewer to test changes
(**Add before making a PR**)_