feat(utilities): make border-radius responsive

[David-S-22]

Description

Add responsive capabilities to border-radius utility to allow for the use of breakpoints. Also updated the border-radius documentation to describe the new functionality and provide an example on how to use it.

resolves #20732

Markup:

<template>
  <div class="d-flex justify-center">
    <v-card
      class="rounded-lg rounded-md-xl"
      width="300px"
    >
      <v-card-text>
        Adjust screen size to see border radius changes 
      </v-card-text>
    </v-card>
  </div>
</template>

[jhanma17]

Disclaimer: First time trying to contribute to an open source project, so sorry if it's not the right way of doing this.

I think you should take a look at rounded.{size} cases. Setting the responsive option to true makes it read the size option as a breakpoint option, e.g., rounded-lg would be read as rounded-md in lg breakpoints instead of rounded-lg in all breakpoints as it's supposed to work.