Migration of EvgenProdTools, first part

In this MR:

• preparation to migrate the EvgenProdTools to HepMC3
• cleanup of the EvgenProdTools, e.g. std:: namespace

This merge request affects 1 package:

• Generators/EvgenProdTools

added Generators master review-pending-level-1 labels

CI Result SUCCESS (hash 1e8607ed)

	Athena	AthSimulation	AnalysisBase	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
AnalysisBase: number of compilation errors 0, warnings 0
AthGeneration: number of compilation errors 0, warnings 0
For experts only: Jenkins output [CI-MERGE-REQUEST-CC7 16399]

The changes look ok. Adding review-approved label.

L1 shifter

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

merged

mentioned in commit 8d622b5a

added sweep:ignore label