Tau trigger: dR combo hypo (ATR-19359)

@jmontejo @aranzazu could you please check you are happy with these changes? I renamed the old dR hypo (for topo selection in tau signature) to dRtt and created a new dR hypo for topo selections in combined signatures. I reused the hypo code developed in ATR-16730 (https://gitlab.cern.ch/atlas/athenaprivate1/merge_requests/4193) which was not merged to 21.1. I had to remove the L1 seed for tau20 otherwise the name of the VBF chains get too long.

I'll check the counts later and remove WIP when you OK'ed.

Does this need to go also to master?