This is safer than just dropping the backend, as .close() will
block if something else is holding the mutex. Also means we can
drop the extra I18nBackend code.
Media syncing still needs fixing.
Some initial testing with orjson indicates performance varies from
slightly better than pysqlite to about 2x slower depending on the type
of query.
Performance could be improved by building the Python list in rspy
instead of sending back json that needs to be decoded, but it may make
more sense to rewrite the hotspots in Rust instead. More testing is
required in any case.
committing the Protobuf implementation for posterity, but will replace
it with json, as Protobuf measures about 6x slower for some workloads
like 'select * from notes'