Genericise the level search repository.

[RealistikDash]

Currently, the API for searching levels has been very clearly influenced by the search endpoint.
https://github.com/RealistikDash/RealistikGDPS/blob/85bd1a13ad78df1122001b2837b54fb996d14ea6/rgdps/repositories/level.py#L567-L583
This is a design issue we wish to avoid to make code as reusable as possible.

Fields such as search_type and followed_list are very clearly logic related and necessitate game knowledge to understand fully. Instead, they should be handled through params such as (take these as examples and not requirements): ignored_levels, required_levels, ignored_user_ids etc. The rest should be handled by the corresponding usecases.