Fixes UBO limits as well, both to use the per-stage Vulkan limit and to
account for driver uniforms now being dynamic.

Bug: angleproject:3561
Bug: angleproject:3633
Bug: angleproject:3605
Bug: angleproject:3443
Change-Id: I07e34923cc1d132e965a0b9c0590c96fc561fab1
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1685877
Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Jonah Ryan-Davis <jonahr@google.com>