Add XCM support for MYTH between Mythos <-> Ethereum via Snowbridge

[AndyT-51]

Please support transferring MYTH between:

• Mythos <-> Ethereum

Here's the example of a cross-chain transaction between these networks: https://mythos.subscan.io/xcm_message/polkadot-8b7d3a08d7deae65713bcf8923ed24998f03caa8

[lw-cdm]

https://discord.com/channels/447263980252037141/1427255228750889062

[PDTnhah]

• Need to add ahAddress in request params
  => Implementing this when there are many incoming user requests