layers: Consolidate VkDeviceMemory maps into a single map

layers: Consolidate VkDeviceMemory maps into a single map

There were three separate maps in core_validation.cpp that used VkDeviceMemory for key.
This change consolidates those maps into a single map with DEVICE_MEM_INFO as the value.
To accomadate this I added data to DEVICE_MEM_INFO struct to track mapped image/buffer
ranges as well as image reference for memory with mapped image.