Mesa Vulkan Drivers Get a Common Dispatch Framework for Better Code Sharing

Mesa 21.1 has merged a common dispatch framework for use by Vulkan drivers to allow for better code sharing and the possibility of some Vulkan extensions to be more easily supported across all drivers. Already at this stage the unifying to a common dispatch framework for Vulkan drivers has lightened the codebase by more than two thousand lines of code (+3.3k, -5.9k). Great seeing the unification take place now and hopefully allow for more code sharing moving forward. This should also help out in the bring-up of new Vulkan drivers in the future like if finally seeing a Nouveau Vulkan driver or for other embedded graphics processors.