feat(VNumberInput): support control holding down

[yuwu9145]

Description

Markup:

<template>
  <v-container>
    <v-row>
      <v-col cols="12" md="4" sm="4">
        <h5>Default</h5>

        <v-number-input 
          v-if="showNumberInput"
          control-variant="default"
        ></v-number-input>
      </v-col>

      <v-btn
        @click="remove"
      >Remove Number Input</v-btn>
    </v-row>
  </v-container>
</template>
<script setup>
import { ref } from 'vue'

  const showNumberInput = ref(true)
  function remove (event) {
    showNumberInput.value = false
  }
</script>

[J-Sek]

I only see potential for improvement around variable naming and maybe avoiding boolean as direction argument. Other than this, it delivers the functionality and I was not able to break it or come up with edge case scenario.

[J-Sek]

• hldDwnReq » holdDownRaf or holdActionRaf

I actually don't care much about the suffix. It can be *Raf, *Frame, *Req. My issue is with saving 2 vowels in hldDwn for no obvious gain. IMO it drags attention contributing to cognitive load.