message: Mudado tipo do course para string e alterado nome para courseId
diff: import { ApiProperty } from '@nestjs/swagger';
  import { Lesson } from '../entity';
  -import { IsString } from 'class-validator';
  +import { IsNotEmpty, IsString } from 'class-validator';
  import { Expose } from 'class-transformer';
  export class NewLessonDTO {
  + @ApiProperty({ type: String })
  + @IsNotEmpty()
  @IsString()
  @Expose()
  - @ApiProperty({ type: String })
  title: Lesson['title'];
  + @ApiProperty({ type: String })
  + @IsNotEmpty()
  @IsString()
  @Expose()
  - @ApiProperty({ type: String })
  description: Lesson['description'];
  + @ApiProperty({ type: String })
  + @IsNotEmpty()
  @IsString()
  @Expose()
  - @ApiProperty({ type: String })
  - course: Lesson['course'];
  + courseId: string;
  }
  