Allow benchmark with automatic rounds + setup function

[cgravill]

Partial version of AB#19173

pytest-benchmark has a simple benchmark() function and a pedantic() function we want an in-between, where we can give a setup function but allow "rounds" to be automatically determined

Potentially propose to pytest-benchmark project adding an optional setup function to the simple benchmark() function, but it's messy as you can't pass args AND setup

[cgravill]

[toelli-msft]

Very handy, thanks!

[toelli-msft]

This works very well!