Show date of last successful filter list download

Background / User story

In case a filter list download fails, an error is shown in the options page but not when the download last succeeded. As mentioned in https://issues.adblockplus.org/ticket/2848 we could add this information as a tooltip on the error message or expose it through other ways.

In case a filter list download fails, we should show the date of the last successful download at the following position:

• current options page: to the right of the error message
• new options page: in a tooltip when hovering over the error message

What to change

• Design: TBD
• Research: TBD
• Spec: TBD

Hints for testers

TBD

Hints for translators

TBD

Integration notes

TBD