Snapshot vk image content in common situation

This commit snapshots vk image content by allocating a staging buffer
and copying the bytes on snapshot. It only works in the simplest setup.
Many situations are not considered in this commit, they include:

(1) the image does not support VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL
layout;
(2) the image does not support VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL
layout;
(3) the queue is dirty.

Also there is no performance optimization.

Implementation-wise, snapshot happens in VkDecoderGlobalState after
recording / playing back all create / bind commands. It borrows an
existing queue to run the extra vk copy commands. A temporary staging
buffer is also created for copying. Later we could optimize the code
by reusing most of the temporary objects.

Reviewed-by: Aaron Ruby <aruby@blackberry.com>
Acked-by: Yonggang Luo <luoyonggang@gmail.com>
Acked-by: Adam Jackson <ajax@redhat.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/27246>

src/gfxstream/codegen/scripts/cereal/decodersnapshot.py

@@ -113,6 +113,7 @@ apiSequences = {
 apiModifies = {
     "vkMapMemoryIntoAddressSpaceGOOGLE" : ["memory"],
     "vkGetBlobGOOGLE" : ["memory"],
+    "vkBindImageMemory": ["image"],
 }
 
 def is_modify_operation(api, param):