Feature request about tab and tabset

[kryon-7]

Thank you for creating such a convenient library - it has saved me a tremendous amount of time! While working with it, I've identified a few areas that could be improved for better usability. Below are my feature requests, which I've already implemented in my fork (though my implementation might not cover all edge cases). I'd love to see these improvements merged into the main branch for ongoing maintenance:

1. Left Button Tool Support: Currently, the tabset only has a right-side buttonTool. I'd like to see the ability to add elements to the left side of the tabset as well. This would be particularly useful for Electron applications where we might need to add a blank element to work around title bar constraints.Alternatively, when the application has a sidebar, it would be ideal to add a button on the left side of the tabset to reopen the sidebar if it's hidden.

2. Customizable DropInfo: When dragging and moving tabs between tabsets, the tabinfo indicator appears with fixed sizing and positioning. I propose making this configurable through globalconfig settings, as the current fixed positioning sometimes creates visual misalignment with dividers, resulting in a less polished appearance.

3. Enhanced Tab Button Styling: The current tabButton implementation could benefit from having separate outer and inner elements. This structural change would provide much greater styling flexibility, particularly for achieving browser-style tab effects (like Chrome's tab styling) where having distinct containers makes the visual implementation significantly easier.