layers: Validate shared presentable image cases

layers: Validate shared presentable image cases

Add validation support for shared presentable images as defined in
VK_KHR_shared_presentable_image extension.

For all uses of shared presentable images, make sure that the image is
appropriately in VK_IMAGE_LAYOUT_PRESENT_SRC_KHR layout.
For two cases where no layout validation was performed, added a TODO
note (vkCmdBlitImage, vkCmdResolveImage) as basic layout validation
should first be added upstream.
Also locked the layout in the case where a front-buffered image is
presented and then flag an error if an attempt is made to transition
the image layout after that point.

Change-Id: I06cda727e3a7f56ccff4bffd7503b5ff73e8a795