Review Metadata section in asset schema

[LudwigFriedmann]

Is your feature request related to a problem? Please describe. (TBD) The chapter is pre-filled based on the information provided from the Miro board. Nevertheless

• descriptions could be more extensive
• Units and data types are missing
• Illustrations would be helpful (e.g, for 7.5.21 bounding box)

Moreover, a reference to the asset file chapter (7.2.4) is missing.

Finally, it should be checked if the asset file documentation and the metadata documentation can be derived from a corresponding json schema file.

Describe the solution you'd like The chapter is reviewed and before-mentioned information is added.

Describe alternatives you've considered

Additional context

[ClemensLinnhoff]

Class-dependent metadata also needs to be added to the asset schema.

[ClemensLinnhoff]

@ClemensLinnhoff will add the data types to the python script generating the asciidoc documentation