Upgrade Monitor to Bootstrap 5

[milleruntime]

Upgrade the Monitor to Bootstrap 5. https://getbootstrap.com/docs/5.0/getting-started/introduction/ We are currently on Bootstrap v3.4.1 (https://getbootstrap.com/). Files located under: src/main/resources/org/apache/accumulo/monitor/resources/external/bootstrap

[nosewings]

I have this in an ugly-but-working state at this branch.

Some things work thinking about:

• Bootstrap v5 no longer comes with the Glyphicon Halflings set, which we use in at least one place. There are some alternative sets out there.
• The styling is significantly different in some places (generally for the worse). This is due both to conflicts with screen.css (fixable) and changes in the way Boostrap does things by default (harder to fix). It's also worth noting that the bootstrap-style.css file is gone; I don't know whether we were doing custom styling with that.

[AlbertWhitlock]

I have put up a PR (#2847) regarding this ticket.

[DomGarguilo]

I have put up a PR (#2847) regarding this ticket.

I'll assign you to this ticket