feat(avatar): Use the first emoji of room names as avatar emoji

[nickvergessen]

☑️ Resolves

• Fix Ability to set an emoji as a conversation avatar #8444

🖼️ Screenshots

🏚️ Before	🏡 After

🏁 Checklist

• ⛑️ Tests (unit and/or integration) are included or not required
• 📘 API documentation in docs/ has been updated or is not required
• 📗 User documentation in https://github.com/nextcloud/documentation/tree/master/user_manual/talk has been updated or is not required
• 🔖 Capability is added or not needed

[jancborchardt]

Looks suuuper cool! :) ✨

[mahibi]

when the conversation name is changed, the emoji is not updated:

[vitormattos]

After merge this PR will be necessary rebase #9423 with this changes and make possible to change the avatar when change the conversation name.

[nickvergessen]

when the conversation name is changed, the emoji is not updated:

It's only the browser caching the image for 24h

[SystemKeeper]

when the conversation name is changed, the emoji is not updated:

It's only the browser caching the image for 24h

Can’t we just get the md5 of the emoji?

[ShGKme]

Can’t we just get the md5 of the emoji?

Do you mean, to calculate md5 for each conversation everywhere?

[SystemKeeper]

Do you mean, to calculate md5 for each conversation everywhere?

For cache busting we need a way to identify if an avatar changed. For default avatars the md5 of the filename is used, for custom avatars I think the hash is already at the filename or something, and for emojis this is added at https://github.com/nextcloud/spreed/pull/9423/files#diff-a7e5eb4728a4ad105af312d21ceb1bd6dd7a70068ba67d4b1881099dcae1076bR289-R291