Add support for AES-192-GCM and AES-256-GCM

[BenCookie95]

Summary

Cherry picked from commit 342698e of the source repo.

Before the change I can reproduce the error in the ticket:

{"timestamp":"2025-05-09 13:24:00.416 -04:00","level":"error","msg":"An error occurred while parsing the response from the Identity Provider. Please contact your System Administrator.","caller":"web/context.go:123","path":"/login/sso/saml","request_id":"cy6ji9zg17gfjq4mjfd5yjk14h","ip_addr":"::1","user_id":"","method":"POST","err_where":"SamlInterfaceImpl.ValidateResponse","http_code":302,"error":"SamlInterfaceImpl.ValidateResponse: An error occurred while parsing the response from the Identity Provider. Please contact your System Administrator., error validating response: unable to decrypt encrypted assertion: unknown symmetric encryption method \"http://www.w3.org/2009/xmlenc11#aes256-gcm\""}

With the change I can login successfully.

Ticket Link

https://mattermost.atlassian.net/browse/MM-64222

[BenCookie95]

This repo hasn't been updated in a while, it's on an old GO version and it's quite a few commits behind the source repo. We probably need a separate ticket to get this repo up to date.