Additional SQLite features

[ncruces]

Please use this issue to request access to additional SQLite features, particularly if they're not part of the amalgamation.

These may be added to the bcw2 module.

Features that are part of the amalgamation, on the "main" branch of SQLite, not deprecated (or superceeded), not recommend against, etc may be added to the embed package, but this is already quite expansive for a default built.