feat(ModemAuthentication): add pin

reach/client/protocol/modem.go

@@ -5,6 +5,7 @@ type SetModemOptions struct {
 	Type     *string
 	Username *string
 	Password *string
+	Pin      *string
 }
 
 type SetModemOptionsFunc func(opts *SetModemOptions)
@@ -34,8 +35,15 @@ func WithUsername(value string) SetModemOptionsFunc {
 		opts.Username = &value
 	}
 }
+
 func WithPassword(value string) SetModemOptionsFunc {
 	return func(opts *SetModemOptions) {
 		opts.Password = &value
 	}
 }
+
+func WithPin(value string) SetModemOptionsFunc {
+	return func(opts *SetModemOptions) {
+		opts.Pin = &value
+	}
+}