[FEAT] Add acme.sh DNS alias mode

[Treppengelaender]

Is this a new feature request?

• I have searched the existing issues

Wanted change

Add support for acme.sh's DNS alias mode (--challenge-alias / --domain-alias) via environment variables.

Reason for change

Some setups require delegating the ACME DNS challenge to a separate DNS zone — for example when the primary domain's DNS provider has no API support or you don't want to leave your API Credentials for the Main Domain on a web facing Machine.
Acme.sh already supports this natively, but SWAG doesn't expose it.

Proposed code change

Nope

[github-actions]

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[Roxedus]

this image does not use acme.sh

[LinuxServer-CI]

This issue has been automatically marked as stale because it has not had recent activity. This might be due to missing feedback from OP. It will be closed if no further activity occurs. Thank you for your contributions.