I found this bug was easily reproduced with any command that wrapped to
multiple rows on the first line of its output. The cause is that we stop
searching for rows once we reach the first one where
`row.semantic_prompt = .command`, which means that we reach the bottom
line of wrapped output and stop there.
This PR makes it so that we continue iterating until we reach a row
where `semantic_prompt != .command` and then return the previous one (or
the last one if we run out of rows).
I also updated the test cases to include this.
I considered that this bug would also be avoided if we didn't propagate
the `command` semantic prompt to additional rows on wrapped lines, but I
don't know enough about the shell integration to make a call on that.
Closes#4693
76fd4fa8df