sqlite transaction behaviors

[markazmierczak]

No description provided.

[mehcode]

I like the idea of doing this, but unfortunately we don't want to accept extensions to the API surface for 0.4. I'm happy to discuss how this can be done in an issue for 0.5 though.

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This is the kind of API I'm currently thinking:

// BEGIN IMMEDIATE
conn.transaction().immediate().begin(&mut conn).await?;

// BEGIN
conn.begin().await?;
conn.transaction().deferred().begin(&mut conn).await?;