Can't upload file with name including characters like ü,ä,ö

Problem/Motivation

Our customer tries to upload a file and it has the word 'für' in it. This needs to be checked and replaced instead if throwing an "General error: 1267 Illegal mix of collations" error.

Steps to reproduce

• Activate the 2.0.2 version of the module
• upload a file with the name "für.zip"

Proposed resolution

Add the check into the uploadIdFromFileId function in the FileFormAlterBase.php line 131

$resup_file_id = iconv('UTF-8', 'ASCII//TRANSLIT', $resup_file_id);