[Developer][Archery] Report both items and bytes per second

[asfimport]

If google bench yields all 3 observations: bytes, items, and execution time, archery will report just bytes_per_second (it trumps items_per_second in archery).

Enhance archery to yield results for both bytes_per_second & items_per_second (if present).

Before:
"ArrayArrayKernel<Add, UInt64Type>/262144/0"

After:
"ArrayArrayKernelItems<Add, UInt64Type>/262144/0"
"ArrayArrayKernelBytes<Add, UInt64Type>/262144/0"

Reporter: Diana Clarke / @dianaclarke

PRs and other links:

• GitHub Pull Request #9431

_{Note: This issue was originally created as ARROW-11517. Please see the migration documentation for further details.}

[asfimport]

Todd Farmer / @toddfarmer:
This issue was last updated over 90 days ago, which may be an indication it is no longer being actively worked. To better reflect the current state, the issue is being unassigned. Please feel free to re-take assignment of the issue if it is being actively worked, or if you plan to start that work soon.