Add button to convert relative time range to absolute

[jackwickham]

Why is this needed:

Often I will be using a relative range to explore some metrics or logs, but I then want to freeze that into an absolute time range to share a link (eg for discussion, to post in a ticket or pull request, etc) so that everyone gets a consistent view. Currently, that means I need to manually convert it to an absolute time range, or hope that there's a time series chart visible that I can drag to select the range on.

What would you like to be added:

A button in the time selector panel when using a relative time, to convert the current relative time into an absolute range.

Who is this feature for?

I think this would be useful for most people who are exploring metrics/logs and might need to share their results with others.