Vendor and use app emojis in more places

[onerandomusername]

We can use app emojis rather than needing to store an id for each emoji: we can store an asset to be used as a back up, fetch all of the emojis, and if the emoji doesn't exist, we can create it using the asset link we have.

# pseudocode

emojis = await monty.fetch_emojis()
for emoji_asset in local_emoji_config:
  if emoji_asset.name not in emojis:
    await monty.create_emoji(emoji_asset.name, emoji_asset.url)

From this point, we can then use the existing emojis for everything. This check may not want to run on every boot, not sure.

This should perhaps be part of a bootstrap script that doesn't get run every time, but that's a different issue.