loginPrivateKey method
adds a new Account and sets the logged pubkey
Implementation
void loginPrivateKey({required String pubkey, required String privkey}) {
if (accounts.containsKey(pubkey)) {
throw Exception("Cannot login, pubkey already logged in");
}
addAccount(
pubkey: pubkey,
type: AccountType.privateKey,
signer: Bip340EventSigner(privateKey: privkey, publicKey: pubkey));
_loggedPubkey = pubkey;
_notifyAuthStateChange();
}