Previously we've placed cursor on the first line of the first excerpt in
the multibuffer, but alas,
https://x.com/fasterthanlime/status/1804883499809165473 happened (j/k,
this feedback is totally valid) and now we're gonna place it at the end
of the first reference. As a bonus, with the old configuration `editor:
select next` tripped over itself. Now it's possible (& feasible) to do a
"select next" in "find all references"; consecutive referenced ranges
will be selected.

Fixes #13419



Release Notes:

- Fixed a bug where "Find all references" editor had cursor placed on
the first line of the first excerpt in the multibuffer instead of having
it on the first reference.