Use specific error for exceptions raised by create_scalar_function

[pydanny]

Typically APSW has more precise errors than Sqlite3, this is one of the exceptions.

When using create_scalar_function in deterministic mode, it is possible to throw an exception based on Sqlite constraints. In sqlite3 this raises a sqlite.NotSupportedError, but there is nothing specific in APSW. In fact, we're not sure what error is raised, so we lump it under apsw.Error. Some better things we can do:

1. Figure the specific error and capture/raise that as necessary
2. If there is no specific error, open a ticket, submit a PR to the upstream APSW library

Note

This is documented as a comment in the register_function code within this library