Improve the Emoji Picker

### Your use case

#### What would you like to do?

Pick emoji faster.

#### Why would you like to do it?

Reactions.

#### How would you like to achieve it?

The best option is probably just throwing away the basic custom emoji picker and calling up the keyboard. This gives a full-featured emoji picker. That being said I don't know if there is a good API for getting one emoji.

If that isn't feasible then the following improvements should be added:

- Sort frequently used emoji first (if we can't use the global keyboard this will need to be app-specific but that is probably good enough)
- Allow pinning "favourite" emoji to the top of the list.

Honestly also take a look at what the popular keyboards do. If we can't use them we can at least learn from them.

### Have you considered any alternatives?

_No response_

### Additional context

_No response_