The patch adds support for both FIFO and non-FIFO mongodb
implementations. It takes advantage of the `uri` scheme to determine
whether the FIFO implementation is needed or not.
A follow-up patch will improve this driver loading phase to match what's
been stated in the spec.
DocImpact
Partially-Implements blueprint: expose-storage-capabilities
Change-Id: Ic25e1893d0bab640ac038097ed89e5b699d5490a
d9faff354d