Creating exhibit with repeated name crashes the frontend.

[pablodiegoss]

Describe the bug
The Exhibit name is a unique field that crashes the page if you try to publish another one with the repeated name

To reproduce the bug

1. Upload an object
2. Upload a marker
3. Create an artwork using both marker and objects that you uploaded.
4. Create an exhibit with the name "Teste"
5. Create another exhibit with the name "Teste" again.

Expected behavior
Show a message "This name is already taken, choose another one."
Screenshots

[brenno-silva]

Since the others pull requests are stalled, can I give a try?

[vjpixel]

@pablodiegoss, how can I check if this is finished?

[pablodiegoss]

@vjpixel follow the steps to reproduce described on the issue. Use the dev environment to create two exhibits with the same name, if you receive a weird page with status 500 written, it's still broken, if you receive a friendly "this name is already taken", it's solved.

[pablodiegoss]

Fixed