UX: Reduce flickering when refreshing search results

[lastzero]

Leaving this.loading untouched in the frontend components that display search results avoids flickering when results are refreshed, which would lead to a smoother experience.

If it doesn't cause any problems or unwanted side effects, the line can be removed in the next step:

refresh(props) {
  this.updateSettings(props);

  if (this.loading || !this.listen) {
    return;
  }

  /*
  TODO: Leaving "loading" untouched here avoids flickering when refreshing the results, which might lead to a
   smoother experience. If it doesn't cause any problems or unwanted side effects, this line can be removed.

  this.loading = true;
  */
  this.page = 0;
  this.dirty = true;
  this.complete = false;
  this.scrollDisabled = false;

  this.loadMore(true);
},

For now, we'll leave it commented out in page/photos.vue and similar search result pages like labels.vue and albums.vue.