Add "over" when timestamp is more than a year ago

What does this MR do and why?

Add "over" when timestamp is more than a year ago

timeago does a floor function and when it reaches years the time range is large so it can be confusing to users.

For example, 2 years and 6 months is shown as "2 years ago". Changing this to "over 2 years ago" makes it clearer.

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Screenshots or screen recordings

This affects everywhere we show relative time:

• Issue header
• Project list

Related to #18607