RegistrationServices: cmake fixes

This package has a component library, but it also exports headers. Define an interface library for the headers.

Also fix library dependencies.

This merge request affects 1 package:

• Database/RegistrationServices

Adding @ssnyder as watcher

added Database master review-pending-level-1 labels

CI Result SUCCESS (hash c66fe977)

	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 12315]

merged

mentioned in commit f4ba60ae

added sweep:ignore label