This PR introduces thread support for channel archives. Now, threaded messages are rendered inside a `details` HTML tag in posts.
The transcript markdown rules now support two new attributes: `threadId` and `threadTitle`.
- If `threadId` is present, all nested `chat` tags are rendered inside the first one.
- `threadTitle` (optional) defines the summary content.
```
[chat threadId=19 ... ]
thread OM
[chat ... ]
thread reply
[/chat]
[/chat]
```
If threads are split across multiple posts when archiving, the range of messages in each part will be displayed alongside the thread title. For example: `(message 1 to 16 of 20)` and `(message 17 to 20 of 20)`.
- Moves `<ChatMessageInfo />` to `<Chat::Message::Info />`
- Moves `<ChatMessageAvatar />` to `<Chat::Message::Avatar />`
- Moves `<ChatMessageLeftGutter />` to `<Chat::Message::LeftGutter />`, adds tests
- Creates `<Chat::Message::Error />`
- Creates `<Chat::Message::MentionWarning />`, adds tests and a styleguide
- Creates a model for ChatMessageMentionWarning, adds fabricator for it
- Keeps the enter/leave viewport logic inside the `<ChatMessage />` component instead of bubbling it to the channel and thread components
- Adds a scale animation when clicking a reaction
- Creates `chat/later-fn` modifier which accepts a function and a delay. It allows to call a function Xms after a component has been inserted, it's useful for animations.
- Moves css code out of chat-message into relevant files
- Deletes unused code
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