AthenaKernel: Add a memory_resource to the EventContext.

Add memResource / setMemResource to ExtendedEventContext, to allow specifying a slot-specific global std::pmr::memory_resource.

This merge request affects 1 package:

• Control/AthenaKernel

This merge request affects 2 files:

• Control/AthenaKernel/AthenaKernel/ExtendedEventContext.h
• Control/AthenaKernel/test/ExtendedEventContext_test.cxx

Adding @maszyman ,@ssnyder ,@gemmeren as watchers

added Core main review-pending-level-1 labels

CI Result SUCCESS (hash 9056a38a)

	Athena	AthSimulation	AthGeneration	AthAnalysis
externals
cmake
make
tests

Full details available on this CI monitor view. Check the JIRA CI status board for known problems
Athena: number of compilation errors 0, warnings 0
AthSimulation: number of compilation errors 0, warnings 0
AthGeneration: number of compilation errors 0, warnings 0
AthAnalysis: number of compilation errors 0, warnings 0
For experts only: Jenkins output [CI-MERGE-REQUEST-EL9 5532] (remote access info)

removed review-pending-level-1 label

added review-approved label

merged

mentioned in commit 15264c2b