Fluent Validation breaks file size validation

[Atulin]

Back when validation was done with attributes, client-side validation for custom validators was a breeze. With Fluent Validation, not the case, as there isn't even any docs that'd describe the process. Nevertheless, client-side validation for it is necessary.

Expected attribute name is either valFilesizeMax or val-filesize-max

• The thing closest to being a solution: FluentValidation/FluentValidation#1314 (comment)
• Issue tracking this... issue: FluentValidation/FluentValidation#1821
• Stack Overflow theread here