Feature: Add file size on upload

Usually, when I upload a log file to issue, I edit the post to include the size of the attachment, so the reader is aware of how big of the download are they expecting

so, perhaps update gitlab to make this automatic?

in tech speak, I make these changes after uploading a file:

-- [slow-20211027.txt.xz](/uploads/9d6e529d1b9b8b2c8051415e13c26899/slow-20211027.txt.xz)
+- [slow-20211027.txt.xz](/uploads/9d6e529d1b9b8b2c8051415e13c26899/slow-20211027.txt.xz) 183K

outcome would be like:

this could be implemented differently:

• perhaps a tooltip on the download link? but that is not so visible to the user right?
• similarly, as the attachment icon is added when rendering, render file size as well?