Resolve "Transform Participant to linkML"

Closes #253 (closed), #252 (closed)

Replaces !186 (closed), !165 (closed)

This MR contains:

• Cleaning up repo: All files which are outdated (.gitlab.ci, yaml files, documentation, ...) are moved to deprecated. The files must be updated in subsequent MRs and removed from deprecated. Please ignore folder deprecated as it contains copy of existing repo content, which is outdated
• Adding linkML yaml files for Gaia-X Issuer, Participant and LegalPerson in folder single-point-of-truth/22.10
• Adding valid instances for Legal Person and Issuer in folder instances
• Adding scripts used in CI/CD pipeline in folder toolchain
• Adding test scripts for shac shapes for LegalPerson and Issuer
• Updating CI/CD pipeline. Now shacl files are created using a fork of linkML, generated shacl files are tested and SD instances are validated with generated shacl shapes
• Updating README files

Here, we will also ensure that

• the output of the CI is provided as packages (in the GitLab package registry) to facilitate passing the artifacts to the Registry. (@langec will discuss with @moosmannp).
• As soon as this is merged, we need to start the translation of the old non-LinkML schema definitions to LinkML, and (see discussion below)
  • delete (a clear overview) any schema definitions that are not in LinkML (i.e., deprecated).
  • and tag the "latest version with 22.10 examples before migration to LinkML" like "v22.10-no-linkml"