.gitlab-ci.yml: add coverage statistics to pytest job

See merge request !63

lib.db: add search params to user db api

See merge request !59

Add a generic pagination result wrapper for static type checking.

Add simple pagination params offset and limit and pass them to the db
implementation.

PaginatedResult should also return if there are more pages ahead, but
this is still todo. It currently just sets more=False.

lib.db: add search params to user db api

See merge request !58

Add name and email as possible "includes"-like search parameters.

The search is quite simple right now and only leverages SQLs LIKE
function. For a more advanced search tools like elasticsearch is needed.

Update dependency uv to v0.6.17

See merge request !62

Update dependency uv to v0.6.16

See merge request !61

Update dependency uvicorn to v0.34.2

See merge request !60

Update dependency uvicorn to v0.34.1

See merge request !57

The else-branch capturing the case if there is a debtor with a high debt
calculated the difference wrong leading to an imbalanced payday result.

A new check at the end of the payday calculation raises a ValueError if
final balance over all users is not 0 per-user as this hints at a bug.
This should be covered by tests, but there are a lot of cases to test.
This can be removed with higher test coverage.