GHA PR Based Pipeline

Between @calebissharp and myself to work on a pr based pipeline using GHA.

The skinny for @ZoeSimon and @LisaMoore1 is this means we can get individual fixes out sooner rather than big bang releases. We can do it now in really sticky situations (and no problem at all for synch job), but it's not very streamlined for the web app or api yet.

I'm making this issue so that it's known to you two that we can switch to what is called a PR based pipeline, which means the test environment looks just like the code in an individual PR, vs everything in the dev branch (what we do now). Doesn't have to be this sprint, but @calebissharp and I might want to look at how much work it would be as getting hotfixes out is important, and we wouldn't get into release limbo as much.

I've set up a jenkins based one for Invasives so I know how it works, but we would be using github actions as jenkins is on its way out and comes with his own suite of issues. @calebissharp had suggested another platform, however NRM and platform services wants teams to steer clear from test environments that aren't openshift like production, so we're going with openshift + github.

@calebissharp @ZoeSimon we should work out what's TODO for this one once we size it all Lisa can decide if it's something we do before the next big round of features/releases (but after this release) or if it waits till later.