fix: Manually approved user registration flow (#29420)

.changeset/registration-flow.md

+---
+"@rocket.chat/web-ui-registration": patch
+---
+
+fix: Manually approved user registration flow
+The new user  gets redirected to the login page with a toast message saying: 
+
+> Before you can login, your account must be manually activated by an administrator.

packages/web-ui-registration/src/RegisterForm.tsx

 import { useUniqueId } from '@rocket.chat/fuselage-hooks';
 import { FieldGroup, TextInput, Field, PasswordInput, ButtonGroup, Button, TextAreaInput } from '@rocket.chat/fuselage';
 import { Form, ActionLink } from '@rocket.chat/layout';
-import { useSetting } from '@rocket.chat/ui-contexts';
+import { useSetting, useToastMessageDispatch } from '@rocket.chat/ui-contexts';
 import type { ReactElement } from 'react';
 import { useForm } from 'react-hook-form';
 import { Trans, useTranslation } from 'react-i18next';
@@ -33,6 +33,8 @@ export const RegisterForm = ({ setLoginRoute }: { setLoginRoute: DispatchLoginRo
 	const formLabelId = useUniqueId();
 	const registerUser = useRegisterMethod();
 
+	const dispatchToastMessage = useToastMessageDispatch();
+
 	const {
 		register,
 		handleSubmit,
@@ -62,6 +64,13 @@ export const RegisterForm = ({ setLoginRoute }: { setLoginRoute: DispatchLoginRo
 					if (/Username is already in use/.test(error.error)) {
 						setError('username', { type: 'username-already-exists', message: t('registration.component.form.userAlreadyExist') });
 					}
+					if (/error-too-many-requests/.test(error.error)) {
+						dispatchToastMessage({ type: 'error', message: error.error });
+					}
+					if (/error-user-is-not-activated/.test(error.error)) {
+						dispatchToastMessage({ type: 'info', message: t('registration.page.registration.waitActivationWarning') });
+						setLoginRoute('login');
+					}
 				},
 			},
 		);