Translation Enablement & consider "seconds" translation

... multiple tr() added for Intervals and Compare Pane
... in Compare Pane - in time metrics check for both "seconds" and translated tr(seconds) (following the concept for time as at most other places where units == "seconds" are checked

(cherry picked from commit 6c78b00b65a1d794eb99038f21d6e705d119d29e)