feat(VDatePicker): add "click:date" event

[luizhenriquerdias]

Description

resolves #21038

Markup:

<template>
  <v-app>
    <v-container>
      <v-date-picker
        @click:date="clickedDate = $event"
      />

      <p v-if="!clickedDate">Click on any date</p>
      <p v-else>Clicked date: {{ clickedDate }}</p>
    </v-container>
  </v-app>
</template>

<script setup>
  import { ref } from 'vue'

  const clickedDate = ref(null)
</script>