Feature Request: Allow Passing Multiple Themes to css-vars() mixin

[desig9stein]

Currently, when adding multiple themes to different components, we need to make repeated calls to the css-vars() mixin:

@include css-vars($input-theme);
@include css-vars($checkbox-theme);

I propose enhancing the css-vars() to allow passing multiple theme maps at once. This would improve code clarity and maintainability, enabling more concise and efficient theming.

Proposed Syntax:
Instead of writing multiple lines, users would be able to pass multiple themes as parameters:

@include css-vars(
   $input-theme,
   $checkbox-theme,
   ...
);

Expected Behavior:
The mixin should iterate through each theme provided and add the corresponding CSS variables.
The output should be equivalent to multiple individual calls of @include css-vars($theme) for each provided theme.
This enhancement would make theme management more streamlined and consistent, improving the developer experience when working with multiple components.