Fix codingjoe#29 -- Do not filter based on empty search term

Split search terms only for __contains queries

Split search terms only for `__contains` queries and not for
`__startswith` or `__endswith`. We no also split not only be
whitespace but tab and newline.

If multiple search fields are defined conditions combined with
and OR. If single word matches in a for contains queries are
OR combined as well.

Co-Authored-By: codingjoe <info@johanneshoppe.com>

Remove colon in example for use with ArrayField

Fix NPM release command

Fix NPM release version

Move deployment to GitHub action

Add Django PyPi classifiers

Enforce https:// for CDN URLs (fixes applegrew#609)

Fix warning in tests

Clear dependent fields on select (applegrew#597)

Co-authored-by: predatell <predatell@bitmessage.ch>