Pass the current http.request to the _update_user backend hook

[devo-devo]

feat: Passes the current request to the _update_user hook. This should allow developers, especially those dealing with multi-tenant sites, to make updates to the user based on the request context. Closes https://github.com/IdentityPython/djangosaml2/issues/350

[devo-devo]

@peppelinux wondering what you're thinking of this? Not 100% sure what a could test for this would be.

[devo-devo]

@peppelinux thank you for your notes! updated.

[peppelinux]

Please devo-devo, can you improve the documentation of djangosaml2, including this additional feature and a short description of your implementation use case and how you did it with the release we're going to make?

[devo-devo]

Will do asap!