Update SDK to include Keycloak as an auth provider.

[michaelconnor00]

Keycloak is not deployed on staging and is still under development. However, the sparkgeo staging deployment is using Keycloak, so it is time to start working on supporting Keycloak for auth.

This will include:

• I do not think Keycloak has a supported SDK, so evaluate the community supported SDKs to determine if they are worth using or creating our own class to manage auth flow.
• Add the Keycloak provider along side (same pattern) as Msal and google. Future release will remove msal and google support, but for the time being, we will need 3.
• Include Test coverage
• Add documentation
• publish new version.
• Update develop to keep the RC package up to date.

Note, the current API key support is good for now. Future releases may have the ability to create new API Keys. TBD.