PyUtils: In checkxAOD, optimise search for category, container name determining
Tools/PyUtils/bin/checkxAOD.py: stop searching for category once a match found, use re.search(ptn) rather than re.match(.*ptn), user re.search() only as needed As a bonus, fix subjesgscIS (DataVectorxAOD::TrigMissingET_v1) [Unknown] to become HLT_MET_mhtpufit_pf_subjesgscIS (DataVectorxAOD::TrigMissingET_v1) [Trig]
Related to ATEAM-960