[Provider][RelyingParty] Revocation endpoint

[peppelinux]

We need to implement this endpoint for Provider and also handle this http request in the rp initiated logout endpoint of the RP

we need to:

• create a view for this

  • in the POST method we need to calidate the client_assertion, as here https://github.com/peppelinux/spid-cie-oidc-django/pull/48/commits/f233568398cbaf1ff809717dd1e319e90c16a4af
  • check if the issuedtoken is still valid and not expired, anyway.
  • revoke the issued token and all the tokens linked to the parent oidc session
  • destroy the user session, see: https://github.com/peppelinux/spid-cie-oidc-django/pull/48/commits/17530d0df60da15eb119417c8eb7e06e6d405e61#diff-95680d9a64d71e280f1266c1cbf174154db4ae2d114ed044aacabb2a8706cf1cR44

• add it in the provider's urls.py file

[peppelinux]

Done here https://github.com/peppelinux/spid-cie-oidc-django/pull/48/commits/4e3637ed19941543bf6c547ddc204df6436f9a8a