TrigConfHLTData: const fixes and interface cleanup

• Remove the duplicate chains() and sequences() accessors. Clients migrated to getHLTChainList() and getHLTSequenceList().
• Remove unused HLTFrame "python methods".
• Some mutable/const fixes to prepare code for thread-checker.

This merge request affects 3 packages:

• Trigger/TrigConfiguration/TrigConfHLTData
• Trigger/TrigConfiguration/TrigConfStorage
• Trigger/TrigConfiguration/TrigConfigSvc

Affected files list will not be printed in this case

Adding @asonay ,@orlando ,@cmorenom ,@mark as watchers

added Trigger master review-pending-level-1 labels

CI Result SUCCESS (hash 785537e4)

	Athena	AthSimulation	AthGeneration	AnalysisBase	AthAnalysis	DetCommon
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
DetCommon: number of compilation errors 0, warnings 0
For experts only: Jenkins output [CI-MERGE-REQUEST-CC7 30391]

What is says on the tin. Approving, -- L1

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

mentioned in commit bff99624

merged

added sweep:ignore label