[Observium] Port 'Last Changed' visibility

Hi all,

I can't seem to see this feature on the port details page or the 'all ports' list but forgive me if it is visible somewhere.

It would be useful to have a 'last changed' time (30 mins ago) etc... on the port details page.

This info can be gained from SNMP and from what I can see is already in the DB so it would just be a case of adding it to the page code.

Thanks

Jake