[configuration] No error when renaming a subproject to a name that already exists

[ridz1208]

Describe the bug
If you rename an existing subproject to a name that is already in use by another subproject, a 500 Error is thrown in the apache error log but no feedback is given to the user, instead the page is simply not updated, not freshed and the change seems to have taken effect until you reload the module

To Reproduce
Steps to reproduce the behavior (attach screenshots if applicable):

1. Go to the Configuration module -> Subprojects
2. chose any subproject and edit its name to match another name in use
3. hit submit

What did you expect to happen?
An error should be thrown saying that the subproject name is already in use

[ridz1208]

@maltheism you can do this in your sleep... but please don't.

• handle the error in the back end
• swal the error in the front end