fix: Invalid JSON in Custom Translations setting crashes the UI

[matheusbsilva137]

Proposed changes (including videos or screenshots)

• Check if JSON code settings (with type: code and code: application/json) are valid before saving, or throw an error otherwise;
• Dismiss custom settings when the custom translations JSON provided is invalid (instead of throwing an error and crashing the UI);
• Fix the Custom Translations setting desciption so that the example is shown as a code snippet.

Issue(s)

Fixes #27846

Steps to test or reproduce

• Go to Workspace > Settings > General > Translations > Custom Translations and try adding an invalid JSON to the field. An error should be thrown displaying "Invalid JSON provided".
• Add a valid JSON to the field and save the changes. Then, try erasing the JSON inserted in the field -- this action should be performed succesfully.

Further comments

TC-554

[codecov]

Codecov Report

Merging #28600 (eadb864) into develop (2eb690e) will decrease coverage by 0.02%.
The diff coverage is 20.00%.

@@             Coverage Diff             @@
##           develop   #28600      +/-   ##
===========================================
- Coverage    45.39%   45.37%   -0.02%     
===========================================
  Files          728      728              
  Lines        14202    14206       +4     
  Branches      2189     2189              
===========================================
- Hits          6447     6446       -1     
- Misses        7448     7455       +7     
+ Partials       307      305       -2     

Flag	Coverage Δ
e2e	45.33% <20.00%> (-0.02%)	⬇️

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