FIX: allows custom groups updates to be reflected without recompilation (PR #9421)


@eviltrout few notes on this:

  • it’s been broken for quite sometimes, but given people don’t add custom emojis everyday, it was not a big issue
  • however with custom groups, that might become more popular
  • I dropped the RAW_TEMPLATE, but kept the precompiled html template from erb which is where the biggest perf gain is
  • tested on android device works fine
  • I took the opportunity to add loading="lazy" as it’s essentially free win when supported, and it is on edge/firefox/chrome, it’s only for custom emojis, but I might apply this to the whole list later