JDK-8208390 moves the internal time base from doubles with varying resolution to Ticks/Tickspan.

This obsoletes a lot of _sec/_ms/* suffixes in method and member names as the type determines its resolution; also we may want to be a bit more specific about whether the (expected) contents are time durations or points in time as just "time" is ambiguous.

Also, over time a lot of different naming at least for G1GCPhaseTime members accumulated, with various pre- and suffixes which are unnecessary.