ODIN-related improvements in HltGlobalMonitor
- Add histograms for monitoring ODIN event types (before and after HLT).
- Rename exiting ODIN histograms for trigger types.
- Remove weird offset (904262401 == 1998-08-28T00:00:01+00:00) in m_gpstimesec and made it a double.
- ODIN histograms after Hlt use Stage to check the correct Hlt[12]Global decision (removed the now unused property HltDecName).