Provide and implement authentication for source registry (and internal registry if necessary)

[frewilhelm]

Description
The storage migration implementation #98 does not use credentials to authenticate against a source registry when copying resources of type OCI artifact in the resource controller.

If we go along with the storage migration (which is debatable see #164), then we either need to use OCM to copy the resources from one registry to another or provide the secrets for authentication using ocm and then pass them to enable oras copy.

Done Criteria

• Check if necessary (Implement a Deployer #146)
• Code has been reviewed by other team members
• Analysis of existing tests (Unit and Integration)
• Unit Tests created for new code or existing Unit Tests updated
• Enduser Documentation updated (if applicable)
• Internal technical Documentation created/updated (if applicable)
• Successful demonstration in Review

[fabianburth]

Postponed until deployment ADR is merged.

[fabianburth]

We decided to pursue the KRO approach. Therefore, we do not need the ORAS copy method call anymore, which was currently unauthenticated. Thus, this issue is obsolete.