Proper error message in OpenProject personal settings if user is not OIDC user

Can't configure integration when oidc app is not installied

Link in 2. Authentication method links to wrong documentation section

Nextcloud app settings: Allow OIDC based connection instead of OAuth2

Allow to use first SSO token for authentication at OpenProject

Setup OIDC auth method using script

Add info about requirements to integration app for OIDC setup

Validate OIDC integration settings when user_oidc app is disabled after complete setup

Handle integration features when OIDC user is provisioned in NC but not in OP

Show proper error message in the Nextcloud Dashboard for OIDC users