fix(server): non-nullable IsOptional (#3939)

* custom `IsOptional`

* added link to source

* formatting

* Update server/src/domain/domain.util.ts

Co-authored-by: Jason Rasmussen <jrasm91@gmail.com>

* nullable birth date endpoint

* made `nullable` a property

* formatting

* removed unused dto

* updated decorator arg

* fixed album e2e tests

* add null tests for auth e2e

* add null test for person e2e

* fixed tests

* added null test for user e2e

* removed unusued import

* log key in test name

* chore: add note about mobile not being able to use the endpoint

---------

Co-authored-by: Jason Rasmussen <jrasm91@gmail.com>

server/src/domain/asset/dto/download.dto.ts

@@ -1,6 +1,6 @@
 import { ApiProperty } from '@nestjs/swagger';
-import { IsInt, IsOptional, IsPositive } from 'class-validator';
-import { ValidateUUID } from '../../domain.util';
+import { IsInt, IsPositive } from 'class-validator';
+import { Optional, ValidateUUID } from '../../domain.util';
 
 export class DownloadInfoDto {
   @ValidateUUID({ each: true, optional: true })
@@ -14,7 +14,7 @@ export class DownloadInfoDto {
 
   @IsInt()
   @IsPositive()
-  @IsOptional()
+  @Optional()
   @ApiProperty({ type: 'integer' })
   archiveSize?: number;
 }