Added method get_native_connection: it retrieves a PyCapsule with MYSQL* C native pointer inside

[tiian]

This extension is necessary to retrieve MYSQL * C native pointer from the underlying C API and pass it to another Python module that requires it.
A PyCapsule object is used to retrieve the pointer.
A use case is described here: https://stackoverflow.com/questions/52687294/how-to-retrieve-mysql-native-connection-from-mysql-and-or-mysqldb-connection#
I have used the same method name that Psycopg2 is introducing in the next version: fogzot/psycopg2@81adddd

Kind Regards
Ch.F.

[methane]

I don't have any interest on XA transaction. I never trust it. I never use it.
I don't want to add public, stable, supported API for expose underlaying data structure.
I'm very tired about replying to questions people asking here (issue tracker, not user forum)...

I'm OK to private API only for your project. It should be private, undocumented, and I don't maintain it.
I don't know how you treat ABI compatibility. For example, MYSQL structure is different between MySQL versions, and MariaDB. You should support all troubles caused by the API.