feat(VExpansionPanels): add more props for customization

[J-Sek]

resolves #21616
closes #12039

• add gap to space out the panels
• add no-divider to hide the line dividing the panels
• extend rounded to cover inner radius when the value is an array

Markup:

<template>
  <v-app theme="dark">
    <v-container>
      <v-expansion-panels :rounded="[20, 8]" gap="4" variant="accordion" no-divider static>
        <v-expansion-panel
          v-for="i in 3"
          :key="i"
          color="primary"
          text="Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat."
          title="Item"
        />
      </v-expansion-panels>
    </v-container>
  </v-app>
</template>