Add tighter integration with 3rd party wallets

[bitgamma]

while Keycard Shell already works with many 3rd party wallets already, it currently requires the user to select the Keystone option in the wallet in most cases. Tighter integration, with a specific Keycard Shell option is desirable.

here is a list of open PR:

Sparrow

• Add Keycard and Keycard Shell sparrowwallet/drongo#31
• Add Keycard Shell support sparrowwallet/sparrow#1853

MetaMask

• chore: add Keycard Shell to the list of supported QR hardware wallets MetaMask/metamask-extension#36911

Specter

• add Keycard Shell support cryptoadvance/specter-desktop#2505

[bitgamma]

cc @guylouis