Optimize db.get_job_matches to paginate on the DB side #372

[MichalJura]

Your checklist for this pull request

• [x] I've read the contributing guideline.
• [x] I've tested my changes by building and running mquery, and testing changed functionality (if applicable)
• [ ] I've added automated tests for my change (if applicable, optional)
• [ ] I've updated documentation to reflect my change (if applicable)

What is the current behaviour?

Currently filtering is done on client side(Python code).

What is the new behaviour?

Filtering(pagination) move to the db side.

Closing issues

fixes #372