It has a wide possible range and the new name ("age" instead of "uptime") is much shorter.
This is a backport of [[https://github.com/bitcoin/bitcoin/pull/20115 | core#20115]] [2/4]
https://github.com/bitcoin/bitcoin/pull/20115/commits/33e987452f869c279f2491499939e51e0af8364c
Depends on D10707