fix: improve sidebar working directory colour contrast with modified files (resolves #5184

[ariane-emory]

Changes the colour used to display the current working directory in the sidebar from mutedText to success, making the working directory more visually distinct from the modified files displayed above it. In most of the stock themes, text seems to be a color that has sufficient contrast to be visually distinguished easily from textMuted.

Examples in some of the stock themes

Cobalt

With this PR: Before this PR:

Matrix

With this PR: Before this PR:

Catpuccin

With this PR: Before this PR:

Resolves #5184.

[rekram1-node]

I think it'd be better to have a space if possible

[ariane-emory]

@rekram1-node I could certainly give that a shot, let me get some caffeine in me first and I'll take a stab at it. Were you imagining adding a single empty line to separate the final line in the modified files section from the first line of the working directory...

1. in addition to this colour change, or...
2. instead of this colour change?

[ariane-emory]

@rekram1-node Alright, pending your response I went with option #1: both. Just let me know if option #2 (spacing only, no colour change) is more your style and I'll make the change. I could go either way myself.

Tokyo Night theme example: