Support `aerospace focus-monitor back-and-forth`

Similar `aerospace workspace-back-and-forth` command which allows switching between workspace in back and forth style, `aerospace focus-monitor back-and-forth` does the same but for monitors ## Details Technically, it's a breaking change since somebody could have had `back-and-forth` monitor pattern, but I highly doubt that... ## Related issues #1024 ## Discussions https://github.com/nikitabobko/AeroSpace/discussions/1868