User::pingLimiter() profiles per action as well

We had an outage beginning of may that involved rate limiting of the
'renderfile-nonstandard' action.  This makes User::pingLimiter() to
record a per action profiling point in addition to the generic one, that
would let us finely graph actions being throttled.

Ref:
https://wikitech.wikimedia.org/wiki/Incident_documentation/20140503-Thumbnails#What_can_be_improved

Bug: 65477
Change-Id: Iac7930e85f7d9101663656ccb2bccdbebf908693
Merge "User::pingLimiter() profiles per action as well"