Feature request: make it possible for users to copy/paste or export Public Key + Chain Code

[olalonde]

It would be nice if it was possible for users to get the "master" public key and chain code from their wallet in the form PUBLIC KEY + CHAIN CODE (or something similar that makes it an easy to copy string. For example,

Pub key = 045a09a3286873a72f164476bde9d1d8e5c2bc044e35aa47eb6e798e325a86417f7c35b61d9905053533e0b4f2a26eca0330aadf21c638969e45aaace50e4c0c87

Chain code = 84ac14bc4b388b33da099a0b4ee3b507284d99e1476639e36e5ca5e6af86481e

Master Public Key = 045a09a3286873a72f164476bde9d1d8e5c2bc044e35aa47eb6e798e325a86417f7c35b61d9905053533e0b4f2a26eca0330aadf21c638969e45aaace50e4c0c8784ac14bc4b388b33da099a0b4ee3b507284d99e1476639e36e5ca5e6af86481e

This would allow users to safely share their wallet with third party services/wallets without having to reveal their root key (Electrum wallet has a similar feature although it uses a different derivation scheme).