RFC: Reorganize Lua scripts folders

The Lua scripts are currently organized into the following folders

• contrib - user contributed scripts maintained by the submitter (supposedly)
• data - used to contain assets required by the scripts
• examples - example scripts
• lib - libraries with common code used by all scripts and maintained by the darktable team
• official - scripts contributed and maintained by the darktable team
• tools - scripts that make the scripts run and odds and ends - maintained by the darktable team

Lately we've started developing/adding scripts that provide a service such as group_persistence.lua which is designed to add tags to grouped images so that the groups are maintained across database instances and can be reconstructed on import.

The scripts aren't meant to be interacted with, though in some instances they can be through shortcuts.

I propose adding a services folder for these scripts, since that's the purpose of them (providing a service).

Thoughts?

As I started I decided why not fix the whole thing. Below is a tree view of my thinking...

Review the current contrib, data, examples, lib, official, and tools folders, along with group_persistence.lua and the proposed services folder. First establish an agreed target organization from the RFC and its follow-up discussion. Done means the folder layout and ownership boundaries are decided and the scripts can be reorganized without breaking their stated uses.