Display toolbox name

[jazzsnobeatcake]

Description

Displays the toolbox name instead of the word toolbox.

Motivation and Context

$hostname defaults to "toolbox" when inside a toolbox.
$tide_toolbox_icon already indicates we're in a toolbox.
Displaying the toolbox name adds further context in multi-toolbox environments.

Screenshots (if appropriate)

How Has This Been Tested

I tested this on Fedora Silverblue 36

• I have tested using Linux.
• I have tested using MacOS.

Checklist

Unsure if these are applicable.

• I have updated the documentation accordingly.
• I have updated the tests accordingly.

[daudix]

This would be really useful 👍

[IlanCosman]

Hi, sorry for the delay on reviewing this. I haven't had access to a linux machine for a while, but will again soon.

[IlanCosman]

Also, external commands like sed, awk, and cat should be replaced with fish builtins such as string match, string replace, and redirection (some_command <file.txt). Makes the code much faster and more portable :)