tmf: Bug 433518: Add support for unit of seconds in TmfTimestampFormat

tmf: Bug 433518: Add support for unit of seconds in TmfTimestampFormat

The T pattern can be augmented with a suffix to indicate the unit of
seconds to be used by the format. The following patterns are supported:
T (sec), Td (deci), Tc (centi), Tm (milli), Tu (micro), Tn (nano).

The S pattern is modified to represent fractions of this unit.

Change-Id: I81014132b7579093da7761861babe0447fd30b0b
Signed-off-by: Patrick Tasse <patrick.tasse@gmail.com>
Reviewed-on: https://git.eclipse.org/r/72840
Reviewed-by: Hudson CI
Reviewed-by: Genevieve Bastien <gbastien+lttng@versatic.net>
Tested-by: Genevieve Bastien <gbastien+lttng@versatic.net>
Reviewed-by: Bernd Hufmann <bernd.hufmann@ericsson.com>
Tested-by: Bernd Hufmann <bernd.hufmann@ericsson.com>