18b947fd00
AssetBus of queued functions until empty. This replicates the old behavior of the EBusQueuePolicy::Execute function that would continue to execute functions if new ones were added during the execution of the current queue. Split the TestFixture class from the AssetHandler and EBus handler for the DynamicSliceInstanceSpawnerTests and PrefabInstanceSpawnerTest. This avoids the AssetMananager destructor from deleting the test fixture if the call to UnregisterHandler is ever removed. This also allows the memory allocators to get online earlier. Signed-off-by: lumberyard-employee-dm <56135373+lumberyard-employee-dm@users.noreply.github.com>