It seems like there are known false positives with thread sanitizer and sqlite.
(There are various references to this in sqlite's wal.c and also possibly
related https://bugzilla.mozilla.org/show_bug.cgi?id=1153409
This adds an app.storage which is a union around configurable storage engine
(currently, only sqlite).
It is _not_ being used anywhere right now. The goal is to get feedback on
the implementation and then move cache to it.
This doesn't expose a generic query API. The goal is that the storage will
expose high level methods, e.g. `cacheGet(req: CacheGetRequest)` and every
storage engine will translate the `storage.CacheGetRequest` as needed.
A thin wrapper around the Sqlite C api is included, e.g. exec(SQL, .{args}) a
`rows` and `row` fetcher. A connection pool is included. By default, an
in-memory DB is currently created. And a `migrations` table with an id of `1`
is created/inserted. I don't imagine needing fancy migratations.