Nomination upgrade dateTime record

[MrJPGames]

Describe the feature you'd like
Imperfect record of when a nomination gets upgraded. Displayed as part of the nomination details on the nominations page.

Describe reasons NOT to add this feature
By definition record of dateTime is based on time of check not the actual timestamp it happened at. Might be confusing to less experienced users.

Describe reasons to add this feature
Left off by default confusion is averted (mostly). And for those that wish for such a feature they can get a better feel for when stuff gets upgraded.

Additional context
Suggested by tehstone on Telegram. Intrest was also shown by Knut P.