Pods 2.5 optimizations work

This is a general PR for all the 2.x-optimizations work done so far by @jamesgol / @pglewis; to ensure we can see a full big picture of the changes. This will make it easier to review everything as it currently is (or becomes) and I can comment on the difference lines.
I figured WordPress handled actions and filters differently, so I went with reproducing what the original code did.  Looking at WordPress I see that everything is basically a filter.  Though I do wonder in this case if the filter should be returning something and not be an action