TrigOutputHandling+TrigCostMonitorMT: cmake fixes
Some cmake fixes for TrigOutputHandling and TrigCostMonitorMT:
- Remove
atlas_depends_on_subdirs
- Add flake8 checking
- Cleanup library dependencies
- Add interface library for public headers
Some cmake fixes for TrigOutputHandling and TrigCostMonitorMT:
atlas_depends_on_subdirs