Remove usages of generic allocator in the layer

Remove usages of generic allocator in the layer

Remove all the leftover instances in layer that still use the
generic allocator rather than the VkAllocationCallbacks

Add additional memory utility that allows to release memory
allocated by custom allocators using RAII

Change-Id: I43594ddd3c506048ca0f02e31b64597a7abc481b
Signed-off-by: Normunds Rieksts <normunds.rieksts@arm.com>