QmlProfiler: Remove dead code from trace file writer

The whitelisting doesn't actually do anything useful. The trace writer
uses a generic method to save range events and only needs specific code
for non-ranges. The compile time checks for the sizes of MESSAGE_STRINGS
and RANGE_TYPE_STRINGS make sure that you can't accidentally leave some
event type unimplemented. The calculation of measured times is obsolete,
too, as the only code the trace writer is called from also sets the
trace time.

Change-Id: Id431630114cb0a0247b774f10874c5caff761436
Task-number: QTCREATORBUG-12496
Reviewed-by: Kai Koehne <kai.koehne@digia.com>