AthenaServices: Add ThinningCacheTool.

Add ThinningCacheTool, which makes thinning requests available to the I/O layer during output.

This merge request affects 1 package:

• Control/AthenaServices

Adding @ssnyder as watcher

added Core master review-pending-level-1 labels

CI Result SUCCESS (hash 93d73413)

	Athena	AthSimulation
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
For experts only: Jenkins output [CI-MERGE-REQUEST-CC7 5281]

Escalating to L2 to review the ThinningCacheTool code. --L1

added review-pending-level-2 label and removed review-pending-level-1 label

The changes look good, marking as approved.

-Jennifer (L2)

added review-approved label and removed review-pending-level-2 label

merged

mentioned in commit 9fd72b0c

added sweep:ignore label