custom charts: Add formatter for the charts

custom charts: Add formatter for the charts

This patch adds some formatter used in the chart.
All of them comes from *.lami.* packages, but with
some modifications to work with our interfaces.

Change-Id: I57ac9edffdd39792e787ead5c15838b3888c920d
Signed-off-by: Gabriel-Andrew Pollo-Guilbert <gabrielpolloguilbert@gmail.com>
Reviewed-on: https://git.eclipse.org/r/77157
Reviewed-by: Hudson CI
Reviewed-by: Genevieve Bastien <gbastien+lttng@versatic.net>
Tested-by: Genevieve Bastien <gbastien+lttng@versatic.net>