feat: support tabsCss property

[henrymyers]

Description

The file uploader currently supports passing in custom CSS for iframe tabs (e.g. Instagram, Facebook, etc), yet I didn't see any clear way of doing so through react-widget. This can now be accomplished for both the Widget and Dialog components via the tabsCss property. The value passed in can be either a CSS string or an absolute file URL.

// Via URL
<Widget tabs="facebook" tabsCss="https://site.com/styles/uc.tabs.css"/>

// Via plain CSS
<Widget tabs="facebook" tabsCss=".source-facebook { background: #1877F2; }"/>

Resulting widget

Checklist

• Tests (if applicable)
• Documentation (if applicable)
• Changelog stub (or use conventional commit messages)

[jeetiss]

thank you for the PR!

[henrymyers]

My pleasure! Would it be possible to bump the version and publish soon so I can access this new feature without pointing to my fork?

[jeetiss]

yes of course

[jeetiss]

@shipjs prepare

[github-actions]

@jeetiss shipjs prepare done