This makes ResourceManagers use more common code. It uses static
polymorphism to implement the various typed resource managers,
and unifies the FramebufferManager into a TypedResourceManager.
The lack of virtual calls and inlining in the header should keep
performance high.

This will make the upcoming refactor to add a destroy hook
for Vulkan objects simpler to implement.

TEST=manual performance testing of BindingPerf.
BUG=angleproject:1684
BUG=angleproject:1639

Change-Id: Ic2f102196020d1005e63a1b2cf0867577fc7c885
Reviewed-on: https://chromium-review.googlesource.com/439488
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>