Support SEP-52 Shamir Secret Sharing backup and recovery

[tupui]

What problem does your feature solve?

Allow users to split their key pair so that they could have a more complex backup solution on their end. Ledger supports it via their paid backup service. Decaf does that as well in the background.

What would you like to see?

Shamir Secret Sharing is an established way to create a distributed backup of a key. We have a SEP on it now with SEP-52. I would like to see a support for it. Tresor has the feature for instance.

What alternatives are there?

Current backup methods.