WIP Introduce TrigCaloInterface.py. Have trig calo clients use this module rather...
This merge request fulfils need for a single point of access described in ATR-24678.
It replaces !48606 (closed). The location of TrigCaloInterface has been moved due to objections to using the TrigCaloRec package made in !48606 (closed). The new location, TrigT2CaloCommon, can still be changed.
The following diagrams show the changes to the import relations: