Graph plugin, add filter regular expression and period time

Filter with regular expression (include and exclude) for label
Filter a test period between 2 intervals.

The new filter interface looks like:
Add Check to add regular expression filter (include or exclude)
Add Start offset (seconds) relative to the first timestamp in the logs (result) file
Add End offset (seconds) relative to the first timestamp  in the logs (result jtl, csv) file

Regards,
Félix H.