[Task] Improve AASX2SAMM generator

[BirgitBoss]

Is your task related to a problem? Please describe.
With #500 a new command line tool "input: AASX file. output: SAMM" was created (aas <aas file> to aspect). Up to now a rough skeleton on first level is generated as basis for manual finalization. However, much more could be automatically generated. Especially for lists (SubmodelElementList) and SubmodelElementCollection improvement is crucial. The generation should be done recursively for the elements in the aasx model.

• if concept descriptions are available a (nearly) complete generation is possible
• if no concept descriptions are available then the adequate characteristics like set or entity should be added based on the type of the SubmodelElement