Update HltEfficiencyChecker examples/docs to latest HLT2 reco binds

Following nice changes upstream in Moore, we can now use the hlt2_binds imports to get all the latest HLT2 binds, rather than having to reproduce them and change them every time they change upstream.

I also take this moment to do:

• make the default configuration to be with UT, and also allow a without UT option. The corresponding keywords in the HltEfficiencyChecker yaml are now latest and without_UT.
• Update the printouts and plots with TrueSim efficiencies, since they're being restored soon in another open MR,
• Update to much newer signal MC samples for efficiencies.

TODO:

• Testing locally
• Look over docs again for any more updates.
• Update example results if necessary
• Tweak n_events in examples if necessary
• Last check on the docs

Should wait for !1117 (merged) so a) make sure I didn't break the docs, and b) so the docs get deployed immediately after merge.