Added 'paid' algolia filtering to search endpoint

[Kandeel4411]

Hello!
Refers Issue #194

I have added 'paid' attribute filtering to the search endpoint using algolia filters, due to not having API key I haven't been able to test it thoroughly.

Possible issue I noticed ( unrelated to this PR ) is that the algolia query API search has a limit of 512 characters where if the user typed a really long query, it would return a 500 error

Let me know if there is anything else I can do, this is my first time 😅

[aaron-junot]

@Kandeel4411 Thanks for your contribution, I'll review shortly. Regarding your comment about the 512 character limit, can you open an issue in the repo for it and I'll assign you to fixing it? I assume you're willing/able to address it considering that you brought it up 😅

[aaron-junot]

We're looking good so far! Can you please add unit tests and documentation?

The unit tests are really just checking that the application doesn't blow up in the situations where paid is included and excluded from the query. The current tests for the search endpoint already check for when it's excluded, so it should just be a simple addition of the parameter in another request and checking that the response is still 200.

The relevant documentation is located here https://github.com/OperationCode/resources_api/blob/master/app/static/openapi.yaml#L87

[aaron-junot]

Looks great, thanks for your contribution!