Fix case of SAMM model elements generated from AAS

[atextor]

Description

When creating Aspect Models from AAS, use the case according to the naming rules.

Fixes #676

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works

Additional notes:

This PR introduces the IDTA submodels repository as a git submodule in the
esmf-aspect-model-aas-generator/src/test/resources directory, so that systematic
translation tests can be done based on the original sources.

[Yauhenikapl]

LGTM!