feat: xcm for stable coin

[Ad96el]

fixes KILTProtocol/ticket#312

Please include a summary of the changes provided with this pull request and which issue has been fixed.
Please also provide some context if necessary.

Metadata Diff to Develop Branch

Peregrine Diff

Spiritnet Diff

Checklist:

• I have verified that the code works
  • No panics! (checked arithmetic ops, no indexing array[3] use get(3), ...)
• I have verified that the code is easy to understand
  • If not, I have left a well-balanced amount of inline comments
• I have left the code in a better state
• I have documented the changes (where applicable)
  • Either PR or Ticket to update the Docs
  • Link the PR/Ticket here