[replace-across-files] Unify the Search Results Panel FindInFiles/ReplaceAll

@njx I just merged with master, and fixed several issues. I wasn't able to move all of the update code to the global search panel, since in this PR i just merged the display of the results and not the actual searches. We will need to move some of the search code into the results classes before we are able to move the auto update functions to the Search Results class.

Your branch is a bit behind master, so there are a few extra commits here. I guess that might not be much of a problem since this PR just mainly touches FindInFiles, and FindReplace, plus a few tempaltes and adds a new SearchResults file. But I just wanted to create a new PR.