feat: add requiredVariants option for mandatory variant enforcement

[micnic]

Description

This PR adds the requiredVariants option for mandatory variants, that is an array of strings representing a part of defined variants, they are checked at runtime and will throw if the user did not provide them.

Usage example:

const buttonVariants = tv({
  base: 'cursor-pointer',
  variants: {
    intent: {
      primary: 'bg-blue-700',
      secondary: 'bg-gray-500'
    }
  },
  requiredVariants: ['intent']
});

buttonVariants({ intent: 'primary' }); // TS will expect `intent` to be provided

What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

[jrgarciadev]

@wingkwong please check

[jrgarciadev]

@tianenpang @wingkwong please check

[wingkwong]

1. please resolve conflicts.
2. if a default is provided, then the variant must be there. required variant for this case seems counterintuitive.

[wingkwong]

please supplement in docs. Currently this section doesn't exist.

[micnic]

Added a PR in the docs repo: heroui-inc/tailwind-variants-docs#48

[micnic]

2. if a default is provided, then the variant must be there. required variant for this case seems counterintuitive.

What would be the expected behavior when both defaultVariants and requiredVariants contain the same variant? Should I filter out the defaultVariants from the requiredVariants check in runtime and types declaration? @wingkwong