Compute authservice redirectUri

[rjferguson21]

Currently the authservice implementation uses the first redirectUri specified in the Package sso block as the callback_uri in the authservice configuration for the mission app.

Ideally we would compute an arbitrary callback_uri and include that URI as an acceptable redirectUri in the Keycloak client. This would avoid scenarios where users can specify a URI that is incompatible with authservice (Keycloak allows globs in the redirectUri).

Steps to implement this fix:

• Replace the callback_uri in the authservice buildChain function with a computed value that is: https://hostname/login
• Update the Keycloak client creation logic to ensure the computed URI is added as an additional value (https://hostname/login ) in the client.redirectUris