fix(db): submission datetime

[aldbr]

Closes #341

Note:

• I disable inherit_cache in date_trunc because I had weird results when calling the search endpoint multiple times in a row.

• The time_resolution does not seem to be part of the cached keys and whatever is the first time_resolution to be used becomes the "reference" in subsequent calls.

  Example:

  WHERE strftime(?, "Jobs"."SubmissionTime") = ?) AS anon_1

  Here ? seems to be replaced with the first cached value instead of the one we want to use.

• I haven't found an easy way to include the time_resolution parameter in the cache keys, but my knowledge of sqlalchemy is very limited, and I might have overlooked something.

• If you want to easily reproduce the issue, you can just switch inherit_cache to True and execute the tests.