[API][Admin/StreetCode page/Tags] An admin can create an identical tag through the creation or updating of a streetcode

[SophiaMRI]

trafficstars

Environment: All Reproducible: Always Build found: 79fb490

Steps to reproduce

1. Add all necessary data to the body.
2. Add an object with an existing tag with id 0 (e.g.: "tags": [
   { "id": 0, "title": "Інтелектуали", "isVisible": true, "index": 0, "streetcodeId": 1385, "modelState": 2 } ], ).
3. Click the 'Send' button.
4. Open the list of tags on the admin side.

Actual result

1. The 200 OK status in the response.
2. The tag becomes duplicated in the list of tags.

https://github.com/ita-social-projects/StreetCode/assets/135108144/003ed4ec-cb8e-440b-bc03-514a135025e2

Expected result The 400 status in the response.

User story and test case links User story #20

[sashapanasiuk5]

Fixed in https://github.com/ita-social-projects/StreetCode/issues/308