WIP: Add a decorator baseclass for b-tagging

This is a part of the initiative that started with ATLASRECTS-4864.

Quite a few b-tagging tools inherit from either IJetModifier or ISingleJetModifier, which is a bit overkill given that b-tagging should never modify a jet. What we do is add a link to the b-tagging object and modify / decorate the b-tagging object.

There are already a number of b-tagging tools that could be run more flexibly (i.e. on locked jet collections, without duplicating and overwriting them) if we used a const xAOD::Jet interface rather than the modifier one. I'd like to start putting these tools into a the more restricted interface: even if the release 22 tools take a slightly different form it will be useful to factorize the code a bit.

I should ask for suggestions from @lidiaz, @guirriec, @cschiavi, @cvarni, @williams, @khoo, @wbalunas, and @loch about how this interface should look.