Set journal mode on create rather than open.

[ChrisPenner]

Overview

We previously set the journal mode to WAL every time we opened a connection, this likely because we would switch the journal mode to DELETE when pushing to ensure the database was fully synced from the .wal file.

Since then, we've done a lot of work to ensure our codebase connections are better managed, and no longer need to set DELETE mode on push because we close connections correctly before pushing.

Now, since we never switch away from WAL mode there's no reason to explicitly set WAL mode on every connection, and it's causing some issues in the Share server since we open the codebase for every request and setting the journal mode is requires locking the whole DB.

So, now we can just set WAL on every new codebase and assume all existing codebases are already in WAL mode.

Implementation notes

• Set WAL mode when creating a new sqlite DB rather than on every new connection.
• Also set WAL mode when pulling from git repos, since it's possible some old codebases still exist which were pushed in DELETE mode.