eza: add support

[cgahr]

Quite recently, added support for theme files (see i.e. https://github.com/eza-community/eza/pulls?q=is%3Apr+themes+is%3Aopen).

AFAIK, these changes are so far only on git and there has to be a public release with theme support, but it would be nice to support it in stylix when it comes available.

[autra]

Changing terminal colors also changes eza colors if I'm not mistaken. In the context of stylix (where everything is styled the same), is it really useful?

[trueNAHO]

Changing terminal colors also changes eza colors if I'm not mistaken. In the context of stylix (where everything is styled the same), is it really useful?

Yes, unless an explicit eza theme improves color quality, we could simply rely on eza using the terminal colors.