core (memory/sqlite): new database schema (v9): this new schema brings the new `public_id` column, which will be used to serve files via HTTP, splits `mime_type` in 2 (`media_type` and `media_subtype`) to make indexing/media filtering easier, and fixes indexes for `files` table.

# XXX: the Monkey Patch is here and not in src/__init__ to avoir issues with pyjamas compilation
# TODO: remove this when changes are merged in Wokkel
from sat_tmp.wokkel import install
install()