fix(cli): measure cwd from cli client rather than the zellij server

[imsnif]

Previously, we would measure the relative cwd (or the lack of cwd) given in a cli command from the zellij-server. This is not the correct behaviour and we should instead measure it from the CLI client.

If I do:

// /home/aram
$ zellij
$ cd code/zellij
$ zellij edit ../file.txt

I expect Zellij to open the editor to /home/aram/code/file.txt and not to /home/file.txt as we did until now.