Migrate to Qt5 from Qt4

[skincell]

I hope y'all are faring well in these tough times!

Feature Request: Migrate to Qt5

About: The current setup relies on Qt4 through the qtbindings ruby library.
Qt4 is now unsupported since 2015, but now Debian and Ubuntu have removed Qt4 from its own package repositories. This is a conscious decision on their part. The Qt team has now also started on Qt6.

Is your feature request related to a problem? Please describe.
I wanted to put Ubuntu 20.04 onto my new company laptop, but I then learned that I could not use COSMOS without compiling from source qt4 (which I had difficulties with and did not accomplish) or using someone's else's packaged qt package. Which I could not do, since I have no way to verify that the source was secure or trustworthy.

To get work done, I've switched back to Ubuntu 18.04 for now.

Describe the solution you'd like
A migration from the project using Qt4 to Qt5, or to get someone to update qtbindings.

As qtbindings is apparently made by parts of Ball's team, or it could be done by switching to a different library if it exists. Also another reason, I'm bringing it up here instead of qtbindings is that this is project that qtbindings was made for, and a motivation to change has to come from here.

Additional context

I know how to solve this problem myself on my side by either using a VM or a docker(Could also set up my own) when I want to use COSMOS, but I wanted to raise this feature with y'all to document your thought process on this. As I am thinking that the docker image was an attempt to head off problems like this.

I'm also hoping people using COSMOS will end up here from Google when dealing with the issues that I just dealt with.

Thanks for your assistance and time!

[ghost]

See #1171

[skincell]

Thanks!