Increase verbosity of Geo2G4MaterialManager when duplicate material names are detected

Currently the additional messages are just at INFO level, but once we have followed up on the current list of duplicates (see ATLASSIM-4679) these messages will be upgraded to WARNING level.

Some variable names within the Geo2G4MaterialManager code have also been renamed to make the code more readable.

This merge request affects 1 package:

• Simulation/G4Utilities/GeoMaterial2G4

Adding @jchapman ,@vpascuzz as watchers

added Simulation master review-pending-level-1 labels

CI Result FAILURE (hash dd7946c0)

	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 19081]

Only failing test is the trigger/MC test, resolved in another recent MR. Code changes look fine, approving.

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

merged

mentioned in commit cb96b322

added sweep:ignore label