fix(VTreeview): prevent redundant treeview re-render during open

[yuwu9145]

fixes #19919

Description

• Open action SHOULD NOT trigger any re-rendering
• VTreeview has redundant re-rendering from v-model:opened change
• This fix should prevent some of redundant renderings and enhance performance noticeably
• After this PR, the remaining redundant rendering should be resolved in the upstream library babel-plugin-jsx

Markup:

<template>
  <v-treeview 
    :items="items"
    @update:opened="openedUpdate"
    ></v-treeview>
</template>

<script>
  export default {
    computed: {
      items: () => {
        const GetChildren = id => {
          const nodes = []
          for (let i = 0; i < 100; i++) {
            nodes.push({
              id: `${id}-${i}`,
              title: `Example child item ${i}`,
            })
          }
          return nodes
        }
        const nodes = []
        for (let i = 0; i < 100; i++) {
          nodes.push({
            id: i,
            title: `Example item ${i}`,
            children: GetChildren(i),
          })
        }
        return nodes
      },
    },
    methods: {
openedUpdate: function(e) {
  console.log('openedUpdate', e)
}
    },
    data: () => ({}),
  }
</script>

[yuwu9145]

Avoid non-existing prop being assigned as undefined to VList

If @update:opened="openedListener" is used in Treeview, VList.filterProps(props) is equivalent to <VList :opened="undefined" @update:opened="openedListener">, which breaks VList demo

[johnleider]

This does provide an improvement, but it's still very slow and only appears to work when opening and closing a single group. When you move to the next one or back, it's still a 2-3 second delay before it displays.

[yuwu9145]

This does provide an improvement, but it's still very slow and only appears to work when opening and closing a single group. When you move to the next one or back, it's still a 2-3 second delay before it displays.

The remaining latency is caused by vuejs/babel-plugin-jsx#712. If you remove v-slots usages in lines 120, 129 & 138 in VTreeviewChildren.tsx on top of this PR, expanding will be zero latency.