The name hw queries was choosen as occlusion queries are 'feeling'
like nothing special. It is possible to interact with them only
via the command stream - unlike perfom queries where some kernel
magic is needed.

Accumulated HW queries is a much better name for this type of queries.
We read some hardware values over some draw calls and need to accumulate
them to get the final result.

This is some prep work for the following perfmon changes.

Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Part-of: <mesa/mesa!1530>