Removed dead code for properties unification

After introduction of GaudiConf2 configurable the properties unification is taken over by classes defined in AtlasSemantics. This MR removes dead code in UnifyProperties. Only one trivial function was used from this package. Tagging @wlampl and FI @delsart

This merge request affects 1 package:

• Control/AthenaConfiguration

Adding @ssnyder as watcher

added Core master review-pending-level-1 labels

CI Result SUCCESS (hash 37bd00e5)

	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 22297]

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

merged

mentioned in commit d00ae0fb

added sweep:ignore label