Store enabled instance and device extensions
Stores the enabled instance and device extensions during vkCreateInstance and vkCreateDevice respectively. This fixes an issue where function pointers for functions of disabled extensions were returned during vkGetInstanceProcAddr/vkGetDeviceProcAddr.
Adds functionality for adding extensions that belong to a subset of other extensions in util::extension_list.
Adds function for checking if the proper surface extension has been enabled in each WSI backend.
Signed-off-by: Iason Paraskevopoulos iason.paraskevopoulos@arm.com Change-Id: If5e23e0d07c9f09006be18c410c4e1d4c3a1e676