I've corrected some obvious issues, and we can fix others over time.
Mypy tests are currently broken, as adding the type hints has increased
mypy's testing surface.
we need to switch to autocommit mode before executing vacuums &
certain pragmas
also removed the pysqlite version workaround; we just use the
python-provided versions in all cases now as it is new enough
- tweak sync code so that a failure in loading the collection
won't leave the app with an unopen collection
- don't show corrupt collection message when the error is not
a db error
- catch the temp folder issue when loading the collection. i suspect
this was the issue that was causing some people to end up with
an open anki instance with no collection loaded
