swh.indexer.storage: Open content_mimetype_get_range
This opens one storage endpoint to allow content retrieval on the mimetype table with range.
This is a first step as other endpoints needs opening as well.
Related #991 (closed)
This adds the hypothesis test module to improve tests writing (no more data hard-coded, we generate those)
Changed the data sample from sets to ordered list.
Test Plan
tox
Migrated from D654 (view on Phabricator)