Introduction of calibration devices in Database

[GernotMaier]

Related to Tobias work on the Illuminator model, see PR #802.

The illuminator model should be added to the database.

• add new collection calibration_devices to Staging-CTA-Simulation-Model
• new branch in `model_parameters repository (see here) with illuminator directories. This should be used to develop the schema files for the illuminator model and review the parameters before submitting them to the database.
• check where changes are required in simtools to allow to access this collection (possibly discuss if we shouldn't have a single point of reference for the list of database collections

[GernotMaier]

Added the collection to the database.

[GernotMaier]

This has / will be addressed in:

• PR Integrate light emission #802 by adding illuminators
• PR Read simulation model versions from DB #927 by adding a db.get_collections