Migration of the last portion of GeneratorFilters to HepMC3

In this MR:

• Migration of the last portion of GeneratorFilters to HepMC3.
• Relatives.h header for the HepMC3.

This merge request affects 2 packages:

• Generators/AtlasHepMC
• Generators/GeneratorFilters

added Generators master review-pending-level-1 labels

CI Result SUCCESS (hash 04d09256)

	Athena	AthSimulation	AthGeneration
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
For experts only: Jenkins output [CI-MERGE-REQUEST-CC7 17679]

added review-user-action-required label

removed review-pending-level-1 label

resolved all threads

added review-pending-level-1 label and removed review-user-action-required label

added 77 commits

• 04d09256...e8df3bb2 - 75 commits from branch atlas:master
• a2ab8202 - Fixes
• ea386c67 - Merge remote-tracking branch 'upstream/master' into HM3GeneratorFilters9

Compare with previous version

This merge request affects 1 package:

• Generators/GeneratorFilters

CI Result FAILURE (hash ea386c67)

	Athena	AthSimulation	AthGeneration	AnalysisBase
externals
cmake
make
required tests
optional tests

Full details available on this CI monitor view
Athena: number of compilation errors 1, warnings 0
AthSimulation: number of compilation errors 0, warnings 0
AthGeneration: number of compilation errors 1, warnings 0
AnalysisBase: number of compilation errors 0, warnings 0
For experts only: Jenkins output [CI-MERGE-REQUEST-CC7 17780]

added 20 commits

• ea386c67...6a76985f - 18 commits from branch atlas:master
• ace61581 - Merge remote-tracking branch 'upstream/master' into HM3GeneratorFilters9
• 16254e53 - Fix

Compare with previous version

This merge request affects 1 package:

• Generators/GeneratorFilters

CI Result FAILURE (hash 16254e53)

	Athena	AthSimulation	AthGeneration	AnalysisBase
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
For experts only: Jenkins output [CI-MERGE-REQUEST-CC7 17792]

CI failure unrelated and now fixed

Jenkins please retry a build

This merge request affects 1 package:

• Generators/GeneratorFilters

CI Result SUCCESS (hash 16254e53)

	Athena	AthSimulation	AthGeneration	AnalysisBase
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
For experts only: Jenkins output [CI-MERGE-REQUEST-CC7 17802]