Isolation tool for CharmWG

Taking inspiration from !2147 (merged), particles in the cone angle of the decay can be persisted in the DST with the function make_iso_particles(input, coneangle = 2., cone_for_each_track=False) defined in isolation.py and added as extra_particles in the definition of the line.

This is implemented in rare_charm_lines.py, serving also as an example.

Depends on: Rec!3434 (merged), Rec!3444 (merged), Rec!3441 (merged)

It superseed !2378 (merged), ie. it already includes the new lines of this MR

Rec!3456 (closed) allows only for the removal of duplicate candidates among the attached extra_particles and therefore shouldn't have an huge impact

Example to retrive the isolation variables in DaVinci can be found here.