Add more logs to help identify cause of race condition

[marcaaron]

We added some logs in this PR to help see if set() is ever called while the mergeQueue is processing - which would prove a race condition and there have been very few times that it has occurred.

However, the ones that have occurred are really perplexing and all seem related to storage eviction. So we should add more logs to see if we can get anymore information about the error. All happened on web + using Chrome.

[marcaaron]

Catching up on this hunch here and we had 9 logs of this in the past week all were when the cache eviction was triggered for a reportActions_* key and that somehow caused a set() to happen while we had a pending merge set up for a report_*.

Gonna try to re-create a storage eviction event and see why the error causes set() to be called after a merge() and if we can do anything about it.

[marcaaron]

With the addition of IndexedDB, we can probably just ignore this issue for now unless it becomes a problem.