TrigOnlineMonitor: cmake and package cleanup

Remove unused link dependencies, move headers to src directory and delete obsolete plotting script.

This merge request affects 1 package:

• HLT/Trigger/TrigMonitoring/TrigOnlineMonitor

This merge request affects 10 files:

• HLT/Trigger/TrigMonitoring/TrigOnlineMonitor/CMakeLists.txt
• HLT/Trigger/TrigMonitoring/TrigOnlineMonitor/TrigOnlineMonitor/TrigMuCTPiROBMonitor.h
• HLT/Trigger/TrigMonitoring/TrigOnlineMonitor/TrigOnlineMonitor/TrigROBMonitor.h
• HLT/Trigger/TrigMonitoring/TrigOnlineMonitor/share/plotL1TopoROBMonHist.py
• HLT/Trigger/TrigMonitoring/TrigOnlineMonitor/src/TrigMuCTPiROBMonitor.cxx
• HLT/Trigger/TrigMonitoring/TrigOnlineMonitor/src/TrigMuCTPiROBMonitor.h
• HLT/Trigger/TrigMonitoring/TrigOnlineMonitor/src/TrigOpMonitor.cxx
• HLT/Trigger/TrigMonitoring/TrigOnlineMonitor/src/TrigROBMonitor.cxx
• HLT/Trigger/TrigMonitoring/TrigOnlineMonitor/src/TrigROBMonitor.h
• HLT/Trigger/TrigMonitoring/TrigOnlineMonitor/src/components/TrigOnlineMonitor_entries.cxx

Adding @kwhalen ,@wiedenma ,@bernius ,@fwinkl ,@rbielski as watchers

added Trigger master review-pending-level-1 labels

CI Result SUCCESS (hash c8efae52)

	Athena	AthSimulation	AthGeneration	AnalysisBase	AthAnalysis
externals
cmake
make
required tests
optional tests

Full details available on this CI monitor view
Athena: number of compilation errors 0, warnings 0
AthSimulation: number of compilation errors 0, warnings 0
AthGeneration: number of compilation errors 0, warnings 0
AnalysisBase: number of compilation errors 0, warnings 0
AthAnalysis: number of compilation errors 0, warnings 0
For experts only: Jenkins output [CI-MERGE-REQUEST-CC7 27944]

added review-approved label and removed review-pending-level-1 label

merged

mentioned in commit 1599f80c

added sweep:ignore label