Add Passkey login support (#31504)

closes #22015

After adding a passkey, you can now simply login with it directly by
clicking `Sign in with a passkey`.

![Screenshot from 2024-06-26
12-18-17](https://github.com/go-gitea/gitea/assets/6918444/079013c0-ed70-481c-8497-4427344bcdfc)

Note for testing. You need to run gitea using `https` to get the full
passkeys experience.

---------

Co-authored-by: silverwind <me@silverwind.io>

models/auth/webauthn.go

@@ -181,7 +181,7 @@ func DeleteCredential(ctx context.Context, id, userID int64) (bool, error) {
 	return had > 0, err
 }
 
-// WebAuthnCredentials implementns the webauthn.User interface
+// WebAuthnCredentials implements the webauthn.User interface
 func WebAuthnCredentials(ctx context.Context, userID int64) ([]webauthn.Credential, error) {
 	dbCreds, err := GetWebAuthnCredentialsByUID(ctx, userID)
 	if err != nil {