StoreName only ever controlled whether the name passed to an individual
marker call is emitted as an extra MarkerName field on the ETW event; the
profiler's own marker storage always records the name. The old name did not
convey that, so rename it to ETWStoreName.
Also rewrite its documentation, in BaseMarkerType and in markers-guide.md,
to explain when to set it: leave it false when every marker of the type is
recorded with the same name, since the name then carries no per-marker
information, and set it to true only when callers pass a distinct name per
marker and the duplication cost of a copy of that string in every recorded
ETW event is acceptable.
Differential Revision: https://phabricator.services.mozilla.com/D325300
Damien Carver
0653ae5f15