Frontend is too eager when searching for identities

[khvn26]

When searching for identities, frontend requests to /api/v1/environments/{environment_api_key}/identities/?q={search_term} are too aggressive.

We should consider:

1. Lowering the request rate in the frontend somehow.
2. Rate limiting the endpoint in the backend to avoid excess queries blowing up the database.

PR remediating the problem in the backend by adding an index: #5369

[Aisha-gif2003]

Hi @khvn26 , I’m interested in working on this issue. Can you assign it to me?

[srdasdev]

I want to work on this

[matthewelwell]

@1-23-smy sure, please go ahead - I've assigned to you. Let us know if you need any help.

[Zaimwa9]

Closed by #5379