StaticDeviceAttribute Metadata Type

[RedingJeff]

Describe the bug
Currently the StaticDevice metadata field allows the type Optional[Dict[str, Dict]]. But Fiware only allows a very specific Dict structure. Giving any other structure results in a success in Filip, but an uncatched background error in Fiware.

To Reproduce
Steps to reproduce the behavior:

1. Create an ContextDevice containing a StaticDeviceAttribute with the metadata: {"meta": { "test": "1" }}
2. Filip allows this assignment, you can now post the device without error
3. But if you now look in Fiware, no device or corresponding ContextEntity appeared.

Expected behavior
FiLiP tells you, that the assignment of the metadata was not valid, and stops the execution

Fix
Change the type of the StaticDevice metadata field to a BaseModel modeling the allowed structure. The ContextMetadata and NamedContextMetadata modeld in context.py, can probably be reused for this task. The StaticDeviceAttribute metadata field would then have the same structure and logic as the ContextAttribute metadata field.

[github-actions]

Branch 60-StaticDeviceAttribute-Metadata-Type created!