[Enhancement] Add ping as a column

[nikobck]

I think it would be beneficial for the user to know which instance is the fastest from their position.

This would lead to a better user experience and better server load balancing, as the high-ping servers wouldn't be used as much as the low-ping servers (depending on how much the redirect feature is used, of course).

The ping process could be triggered manually if there are concerns about every server getting the IP address, but otherwise I wouldn't see a problem with it being triggered automatically.

[unixfox]

I'm not fond to clutter too much redirect.invidious.io but you can already get the speed of instances like explained here: iv-org/instances-api#32 (comment)

[nikobck]

I'm not fond to clutter too much redirect.invidious.io

I get that, but I feel like that most users won't go through the list on api.invidious.io to find the best instance, but still expect a decent performance.