Split action into before-build and after-build phases

[Fryguy]

Describe the solution you'd like

I'd like to see the action split into the before-build phase and the after-build phase so I can run them separately, as opposed to having the action run the tests itself. This allows me to do things like run an entire workflow in the middle. I think the action should still allow running the full end to end if that's what's needed, but, for example, if a with command is passed, such as phase: before-build, then it will only run that phase.

Describe alternatives you've considered

I've tried doing it manually, but I'd much rather use this action. I've also found another action that does this, but I'd rather use this one as it's more official.