Consolidate cue.conf and worker.conf

[Davide Agnello]

cue.conf used by Cue's API process and worker.conf used by the backend worker overlap several configuration parameters. These configuration files should be consolidated and provided to both the API and Worker processes. If config parameters are independent to either the API process or Worker process (e.g. database connection string), these should be placed in an "extended" configuration file for each respective process.