revsetbenchmark: add a summary at the end of execution The summary list timing per revset making it much more easier to compare revision to each other.

revsetbenchmark: retrieve the benchmark value in python We retrieve the output of the perf extension and print it ourself. This open the door to processing of this data in the script.

revsetbenchmark: get revision to benchmark in a function And move it to proper subprocess call.

revsetbenchmark: convert revision display to proper subprocesscall