+tes added AkkaMetricsKit to ease use with AkkaSpec
+ Improved printing when running from a spec (use info stead of
println), so the results appear after the test name, not before it like
it happens with unbuffered println()
=per #15064 persistence perf spec is now MetricsKit aware
Merge pull request #15256 from ktoso/wip-performanceSpec-processor-metrics-ktoso

=per #15064 persistence perf spec is now MetricsKit enabled