Bootstrap 3 still being compiled

[AlexNetcare]

Currently Fitnesse seems to be mixing Bootstrap 3 and 4. Most things look fine, but the Search for example is not changing the visuals of the tabs correctly.
Here the Text search Tab looks like the active one while the Properties search looks like it is being hovered. But actually the Properties search is selected and active.

It seems that Bootstrap 3 might be interfering with Bootstrap 4. What I found is that in the build.gradle Bootstrap 3 is being compiled using the fitnesse-bootstrap.less file. Maybe this causes the problem.

If that is the case then the Vulnerabilities from #1289 might still be there. I am not really good with Bootstrap but if someone could take a look at it and verify if I am right or wrong would be nice.
It would probably be best to completely remove the compilation of the less files and only use Bootstrap4. Or maybe at this point, even an update to Bootstrap 5 would be conceivable.

[fhoeben]

I'm not that great with Bootstrap either.
Since you've gotten this far already: can you maybe dive a bit deeper and see whether you can make a PR to at least make sure we use a single bootstrap version?

[AlexNetcare]

I created a PR for this here #1516. It seems ok so far but there a probably still some things that need to be changed.