message: feat(frontend): adds transition to preview image in rederer
  for a less jarring experience
diff: >
  <v-fade-transition>
  <div v-show="!hasLoadedModel" class="overlay cover-all">
  - <div ref="cover" class="overlay-abs bg-img"></div>
  + <v-fade-transition>
  + <div ref="cover" class="overlay-abs bg-img" v-show="hasImg"></div>
  + </v-fade-transition>
  <div class="overlay-abs radial-bg"></div>
  <div class="overlay-abs" style="pointer-events: none">
  <v-btn
  @@ -202,7 +204,8 @@ export default {
  alertMessage: null,
  showAlert: false,
  selectedObjects: [],
  - showObjectDetails: false
  + showObjectDetails: false,
  + hasImg: false
  }
  },
  computed: {
  @@ -271,6 +274,7 @@ export default {
  const blob = await res.blob()
  const imgUrl = URL.createObjectURL(blob)
  if (this.$refs.cover) this.$refs.cover.style.backgroundImage = `url('${imgUrl}')`
  + this.hasImg = true
  },
  zoomEx() {
  window.__viewer.interactions.zoomExtents()
  