Add ATLAS_CHECK_THREAD_SAFETY to TrkSpaceTimePoint and TrkTruthData

These two were already thread safe

This merge request affects 2 packages:

• Tracking/TrkEvent/TrkSpaceTimePoint
• Tracking/TrkEvent/TrkTruthData

added Tracking master review-pending-level-1 labels

CI Result SUCCESS

	Athena	AthSimulation
externals
cmake
make
required tests
optional tests

Full details available at NICOS MR-23388-2019-05-14-02-42
Athena: number of compilation errors 0, warnings 0
AthSimulation: number of compilation errors 0, warnings 0
For experts only: Jenkins output [CI-MERGE-REQUEST 38391]

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

merged

mentioned in commit 4957759a

added sweep:ignore label