Add a "nested" group to button to support enable group- styling it in Tailwind

[obulat]

Problem

VButton adds a group Tailwind class to support styling nested elements when the button state changes. For example, if you need the button icon to change background when the button is hovered on, you can add group-hover:bg-dark-charcoal. Before Tailwind 3.2, there was no way of nesting groups, so we could not apply any styles to a button (using TW) when its parent element changed state. This was necessary, for example, to remove the border of the search type button inside the search bar when the search bar is focused.

Description

Tailwind 3.2 introduces nested groups: https://tailwindcss.com/blog/tailwindcss-v3-2#nested-group-and-multiple-peer-support-using-variant-modifiers
We should add a named group to VButton: group/vbutton. This will allow us to also then add named groups to search bar, and style the buttons inner elements whenever the parent element is hovered on or is focused.

Alternatives

We could also use vanilla CSS for that, but we are striving to move everything to Tailwind, so it would be a step back.

[dhruvkb]

This can be taken up as a part of a more comprehensive VButton refresh currently being designed by @panchovm.

[obulat]

Fixed in #1003