[EPIC] - IDProxy stability

[IvoGoman]

Description

The idproxy uses dexidp under the hood to allow JTWIssuer multiplexing in the Greenhouse APIServer.
There are currently some issues with stability when using etcd as the storage backend for DEX.

Objectives

• Replace the Storage Backend used by Dex with Postgres
• Make the OAuth2Client credentials available in the organisation namespace
• Allow to specify additional redirectURL allowed by the IDProxy

Acceptance Criteria

• Dex is using postgres as the backend
• oauth2-proxy can consume the OAuth2Client credentials from the org namepace
• additional redirect URL for oauth2-proxy can be defined

Dependencies

• Dependency 1
• Dependency 2
• Dependency 3

Additioinal Notes

No response