added more security check rules in dtos

src/role/dto/role.dto.ts

@@ -1,11 +1,13 @@
 import { ApiProperty } from '@nestjs/swagger';
-import { IsString } from 'class-validator';
+import { IsString, MaxLength, MinLength } from 'class-validator';
 export class RoleDto {
   @ApiProperty({
     type: String,
     description: 'Role Name',
     example: 'user',
   })
+  @MinLength(1)
+  @MaxLength(50)
   @IsString()
   name: string;
 }