Inserting, updating, and removing entries from a VisibilityScene was made thread safe in a previous change, and now both the MeshFeatureProcessor and DiffuseProbeGridFeatureProcessor update entries at the same time from multiple threads. This leads to an assert in the Culling concurrency_checker, even though this is now valid behavior.
However, we still don't want to be adding, removing, or updating cullables between BeginCulling and EndCulling, which could cause a mismatch between the result of OctreeScene::GetEntryCount and the actual number of cullables in the scene.
-Added soft_lock_shared/soft_unlock_shared to the concurrency checker to allow multiple threads to acquire a lock when that is the desired behavior, while still asserting that nothing tries to acquire a shared lock when the concurrency checker is already locked.
-Update Culling.cpp to use the new soft_lock_shared when adding, updating, or removing cullables
-Added unit tests for the concurrency_checker
-Updated ArrayView unit test to use AZ_TEST_START_TRACE_SUPPRESSION instead of manually checking the assertion count, so that test now passes in release builds which do not assert.