Reduces command submission overhead by reusing fence objects
instead of creating new ones for each submission. Improves
error reporting in case the submission cannot be complete.
vkGetQueryPoolResults may never return if VK_QUERY_RESULT_WAIT_BIT is
set, and may return queries as not available when they should in fact
be available. This would cause indefinite hangs, so instead we return
fake data to query objects if retrieving query data fails.
Command submission now does not synchronize with the device every single
time. Instead, the command list and the fence that was created for it are
added to a queue. A separate thread will then wait for the execution to
complete and return the command list to the device.
