🐛 Return early for no snippets

[kirkkwang]

This commit fixes a bug where the render_snippet method would return ... ... when there are no snippets. This way, in the main application's app/views/catalog/_index_list_default.html.erb file, we can do something like:

<% index_fields(document).each do |field_name, field| -%>
  <% if should_render_index_field? document, field %>
      <div class="search-index-metadata-group metadata-<%= field_name %>">
        <% field_value = doc_presenter.field_value field_name %>
        <%# Don't show the snippets field if it's empty %>
        <% next if field_value.blank? %>
        <dt><%= render_index_field_label document, field: field_name %></dt>
        <dd><%= field_value %></dd>
      </div>
  <% end %>
<% end %>

This way the field label doesn't show up if there are no snippets.

Expected Behavior Before Changes

... ... would appear if there were no snippets

Expected Behavior After Changes

Nothing would appear so in the main application, we can not show the field label.

Screenshots / Video

Before

After