Pasting images from clipboard after a screenshot creates badly named attachments

Related to XWIKI-20314

Reproduction steps

• make the wiki multi-lingual
• add a new supported language (e.g., fr)
• make the new language the default language
• Create a new page or edit an existent one (which is not the sandbox page. It works curiously as expected when using the sandbox)
• Make a screenshot using any tools (tested with default windows tool, win + maj +s, print keybutton, greenshot)
• Paste it into the editor
• Save the page

Expected:

The attachment name should be random.

Actual result:

The attachment name is _fileCreatedFromDataURI_.png

I'm up to provide any info needed.

Thank you,