Add last-reported to secondary_info

secondary_info supports last-changed, last-updated and last-triggered but not last-reported.

Also need this.

Use case.
I have PM2.5 sensor that is normally reported once a minute.
Sometimes value can be the same (zero) for many hours.

I open dashboard and see “value zero, changed 6 hours ago”.
And doubt: is it really constant, or may be there is some problem with integration?

It would be nice to see “value zero, reported 45 seconds” - OK.
Or: “value zero, reported 5 hours” - something is wrong.