nostr : signer: add `bunker_uri` method to NIP-46 client and signer
* Deprecate `NostrConnectRemoteSigner::nostr_connect_uri`
* Deprecate `Nip46Signer::nostr_connect_uri`
Signed-off-by: Yuki Kishimoto
https://github.com/rust-nostr/nostr/commit/e669686ed1a3545f64db23066a590582929d374c