feat(button,package): add class-variance-authority lib, convert button component to use it

[JoltCode]

Summary of CVA

The goal of CVA is to manage styling for different variants of a component more easily (e.g. colors, sizes, and styles), with better consistency.
This removes the need to manage dynamic classes manually.

Variants are defined in the component as classes, and a default variant is also set.
Tailwind-merge can resolve conflicts in classes defined by CVA.

Example

const buttonClass = computed(() => {
  return cva(
    "h-10 px-4", // default classes which are *always* applied
    {
      variants: {
        intent: {
          text: 'text-gray-400' // applied if intent === 'text'
        },
        disabled: {
          true: 'cursor-not-allowed' // applied if disabled === true
        }
      },
      compoundVariants: [ // classes apply if all conditions are true
        {intent: 'primary', disabled: false, class: 'bg-blue-700 text-white hover:bg-blue-600'},
        {intent: 'secondary', disabled: false, class: 'bg-gray-100 text-black hover:bg-gray-50'},
        {intent: ['primary', 'secondary'], disabled: true, class: 'bg-gray-100 text-gray-400'}
      ]
    }
  )({
    intent: props.intent, // pass variant values. eg: "primary", "secondary", "text"
    disabled: props.disabled // pass variant values. eg: false, true
  });
});

[spwoodcock]

Didn't know about it before, but class variance authority is cool!

[spwoodcock]

CVA looks pretty awesome.
Especially useful if you are creating components from scratch.

Looking into RadixUI more, it doesn't seem very configurable.
They allow the size to change for most components & a few other things, but not much!
The button component doesn't even have the ability to be disabled! (unless it's inherited somewhere and I missed it?).

The question we need to decide on is:

• Should we use a headless component library to manage some of the logic for component props (like RadixUI)?
• Or, should we define the components from scratch?

Interested to hear your thoughts too @varun2948