Use external multichain library

[PiVortex]

Problem

This frontend implmements all the multichain logic. People tend to fork this repo to get started with a new multichain project. This should be a lightweight example that just makes multichain API calls.

What needs doing

• Check the multichain-tools library and see if this can be slotted in, this was recently updated following feedback to add support for wallets.
• Give further feedback on the library

Resources

• Multichain tools library