Improve time values on the horizontal axis of the chart #619

Is there an existing issue for this?

• I have searched the existing issues.

Describe the solution you'd like

Currently, the app displays the number of seconds since the beginning of the capture on the horizontal axis of the chart in the Overview page.

For better readability, we should display elapsed time as hh:mm:ss

Note: since only the past 30 seconds of activity are displayed, showing timestamps would be meaningless.

Is your feature request related to a problem?

No response