Inserting into a time-series collection can fail with NamespaceNotFound

As of SERVER-57660, if a time-series collection is dropped while there are concurrent inserts into that collection, there is a small window where the inserts may fail due to the buckets collection being dropped. In order to be more in-line with the behavior of a regular collection, if this race occurs, we could back out of the time-series insert path and perform a regular insert, which would implicitly create the namespace as a regular collection.