Connect Dev Environment (MAS) to BundID IdP

Problem

• The Neo Web client and iOS app requires a login and authentication process.
• The technical breakthrough context prioritizes password and username for login and to authenticate MAS against the BundID in any way possible.
• Therefore we need to connect the MAS available in the dev environment to BundID as upstream IdP based on the concept created in #36.

Goal

• Enable MAS login using BundID username/password in the dev environment as modelled in #36.

ACs

• Implement MAS authentication model for BundID IdP described in #36
• (details to be added after conclusion of #36)

Notes/ resources

• We only want to implement the concept from #36 (only backend, no web app implementation -> #224 , no iOS app implementation -> #223).
• Login through MAS's own web frontend will be possible for testing

Who needs to be involved / informed

• reviewed: team::infra-and-ops
• involved: @kim, Robert, @OC000089249168, team::infra-and-ops
• informed: