fix(fill): Add terminal-width argument to explicitly define terminal's width

[rashil2000]

Description

This adds a new commandline option for the prompt subcommand, called --terminal-width. Without this fix, the fill module does not work on Windows as the prompt functions (of any shell) always assume a non-interactive terminal, which leads to term_size crate reporting a zero width.

This argument's value is only used as a fallback, so it will likely not affect macOS/Linux.

Motivation and Context

Closes #3086

Screenshots (if appropriate):

None

How Has This Been Tested?

• I have tested using MacOS
• I have tested using Linux
• I have tested using Windows

Checklist:

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

[mukul-mehta]

I've tested with zsh 5.8 on macOS and it works

[rashil2000]

@davidkna Do I need to make any more changes?

[davidkna]

Beyond my comments LGTM

[rashil2000]

Done

[chipbuster]

I didn't realize that rebasing onto master doesn't fix the conflict (one of the hazards of rewriting history I guess).

[rashil2000]

Hey @chipbuster
I don't see any conflicts here on GitHub, could you point me towards the problem?

[chipbuster]

I went ahead and resolved the merge conflicts for you (101ced5). Sorry I forgot to follow up in Discord--it was late and I was pretty tired.

[chipbuster]

@rashil2000 Thanks for the fix!