add login flow for waiting list demo app

src/auth/dtos/request/send-login-otp.request.dto.ts

@@ -0,0 +1,9 @@
+import { ApiProperty } from '@nestjs/swagger';
+import { IsEmail } from 'class-validator';
+import { i18nValidationMessage as i18n } from 'nestjs-i18n';
+
+export class SendLoginOtpRequestDto {
+  @ApiProperty({ example: 'test@test.com' })
+  @IsEmail({}, { message: i18n('validation.IsEmail', { path: 'general', property: 'auth.email' }) })
+  email!: string;
+}