This removes the facility in the API router to have limited lists of
extensions. From this point forward, what is in Nova is loaded, no
exceptions.
A number of unit tests and fakes have to be updated to pass after
this, as many unit tests were sending small lists of extensions to the
API router to simplify the responses they were getting back. This also
required stubbing out the request db cache in some cases, because
extensions later get content from there to avoid additional db
hits. As well as adjusting a few samples tests which now return more
data because all the extensions are always loaded.
There is much cleanup to happen after this, but this is the smallest
unit to get us over this boundary which will start letting us to
refold extensions back into the base views (and massively simplify the
API code).
This does not yet remove the config options because there is another
place those get used in servers.py and the testing fallout of that is
much bigger.
The reno will come with that patch.
Change-Id: I3e72f5e23ce39148f31dfdb76d18f403c6d04842
d8673cb256