Split format-related helper fxns out of vk_layer_utils.cpp into a new
file vk_format_utils.cpp.  Remove the duplicated fxns in the render
framework and share the new format utils across both projects.
Rename the util fxns into CamelCase per coding std.

Change-Id: I0f9a34bc5931dfca085dfdc8d4800664aec526cf