Config endpoint
This MR replaces the legacy /configuration endpoint which has been moved to /v2.
The config endpoint provides the following data:
- authentication providers
- enabled features and their settings
- arbitrary UI-specific properties (passed through from config file)
Configuration file handling has been improved and now supports loading from multiple files:
- application.yml
- secrets.yml
- ui.yml
The configuration file has been restructured and now has the following main sections:
- system
- security
- features
- ui