Fix sorting behavior for user email addresses

I submitted this as an issue but was informed that it's working as designed.

I frequently receive lists of users who no longer require access to a VDR, and I've found the easiest way to do this is to do a bulk-removal, sorting by their email address.  

The current sort order prioritizes case (upper/lower) ahead of alphabetical order, which results in sorting such as:

• AZachary@company.com
• Ashley.Smith@company.com
• John.Doe@company.com
• aaron@company.com

A minor but impactful change would be updating this behavior to be truly alphabetically sorted, regardless of case.