This PR makes `?` work with `reject`. For example:
```bash
> {} | reject foo
Error: nu:🐚:column_not_found
× Cannot find column
╭─[entry #2:1:1]
1 │ {} | reject foo
· ───┬── ─┬─
· │ ╰── cannot find column 'foo'
· ╰── value originates here
╰────
> {} | reject foo?
╭──────────────╮
│ empty record │
╰──────────────╯
```
This was prompted by [a user
question](https://discord.com/channels/601130461678272522/614593951969574961/1091466428546306078).
I would like to get this in for 0.78, I think it's low-risk and I want
the `?` feature to be as polished as possible for its debut.
83ddf0ebe2