Merge with hgg-coffea

I open this PR as WIP so that it is clear what I'm doing and I can get regular feedback. At this initial stage I simply did the following:

• copied what is already in hgg-coffea and made it work;
• update all the heavy config files on git LFS in order to avoid symlinking to eos directories and install them along with the package in order to have them "location independent" (feedback appreciated about this, since maybe there are cons that I didn' consider).

From here on I will go down the path of integrating taggers and systematics (since as you can see at the moment there are two versions of both, which clearly doesn't make sense). I anyways thought it was a good idea to open the PR early to make the process as open and visible as possible. I will use the discussion here to ask opinions about some things that will have to be changed (more details in the meeting later today).