feat(VTabs): slots for prev/next

[J-Sek]

Description

resolves #21969

Markup:

<template>
  <v-app theme="dark">
    <v-container max-width="600">
      <v-card>
        <v-tabs
          bg-color="teal-darken-3"
          slider-color="teal-lighten-3"
          show-arrows
        >
          <v-tab
            v-for="i in 30"
            :key="i"
            :text="'Item ' + i"
            :value="'tab-' + i"
          />

          <template #prev>
            <v-btn icon="$prev" rounded="lg" size="small" v-tooltip:left="'Move left'" />
          </template>
          <template #next>
            <v-btn icon="$next" rounded="lg" size="small" v-tooltip:right="'Move right'" />
          </template>
        </v-tabs>
      </v-card>
    </v-container>
  </v-app>
</template>