Remove obsolete jets tools

There are several tools in Phys related to jets which are not used anywhere, as identified in https://gitlab.cern.ch/lhcb-dpa/project/-/issues/8. In particular

• Phys/JetTagging/src/*.* (created in 2015 by @philten and @jwilliam) seem not to be used anywhere.
• Phys/LoKiJets/src/*.* Same as above.

Obsolete code should be removed. None of that is required in DaVinci, so it seems. RTA should see what is needed for Moore.

@wbarter and @rangel are in charge.