added metadata, fix descriptions, fix thumbnail, update tests
thumbnail: quality before: https://peertube.cpy.re/static/thumbnails/d2a5ec78-5f85-4090-8ec5-dc1102e022ea.jpg
quality after: https://peertube.cpy.re/static/previews/d2a5ec78-5f85-4090-8ec5-dc1102e022ea.jpg
description: we were getting about the first 260 characters, we now get full description (with fallback to first 260 chars if the get request for full description fails)
test: updated tests to match description, also changed some test: it was assertEquals(extracted, expected), but the proper way to do it is assertEquals(expected, extracted)
metadata: got host, privacy (public, private, unlisted), licence, language, tags
a281519e77
