Case sensitivity on file endings

We are currently case sensitive on file endings. This is problematic since the file ending could also be in all caps. This can also happen without the user explicitly naming the file as such. For example due to very long paths in windows:

When you create a long file name, Windows may also create a short 8.3 form of the name, called the 8.3 alias or short name, and store it on disk also. This 8.3 aliasing can be disabled for performance reasons either systemwide or for a specified volume, depending on the particular file system.

https://docs.microsoft.com/en-us/windows/win32/fileio/naming-a-file?redirectedfrom=MSDN

This could most easily accomplished utilizing the case insensitive compare of QString: https://doc.qt.io/qt-6/qstring.html#compare-1