Material File's Name with no extension will be regarded as Plain Document upon downloading from Folder

[bivanalhar]

How to Reproduce the Issue

• Upload any file from your computer, preferably with extension (.pdf, .jpg, .docx, etc.)
• After uploading, edit the filename in the Workbin by deleting the extension
• Try to click the "Download Entire Folder" located on the top right of the page

You will see the entire folder being downloaded, and upon accessing the said file, it will be rendered as Plain Document and thus not being rendered properly (for example, if the original file is in PDF, then in the plain document format, the display will be messy and cannot be understood)

Suggested Fix

• Either we don't allow the extension of the file to be deleted (before saving, we need to check if the extension is still there), or
• Give user the warning before proceeding to edit the filename, should they try attempting to do so