Feature Request: Add global configuration option in new Database(options) for transactions (either DEFAULT, IMMEDIATE or EXCLUSIVE)

[titanism]

It would be great if we had a global configuration for BEGIN IMMEDIATE and BEGIN EXCLUSIVE at the new Database() level (as opposed to invoking db.transaction(() => {}).immediate();).

[mceachen]

I think this would be nice (but I don't have the final say here).

This would be a JS-only change, so it might be a reasonable “first PR” task for someone to swing at.