This implements a notification to the Framebuffer that an attachment
had a state change that might require recreating the VkFramebuffer.

This implementation is much simpler than the prior method with
signal notifications. Only currently implemented for TextureVk but
will also be implemented for RenderbufferVk.

Bug: angleproject:2347
Change-Id: I05f7da4132f6ed2bda02671e8ba5ee9805252928
Reviewed-on: https://chromium-review.googlesource.com/930024Reviewed-by: Luc Ferron <lucferron@google.com>
Reviewed-by: Yuly Novikov <ynovikov@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>