Add Quick Reactions to EmojiDialog

The commonly-used message reaction emoji is 👍 ❤ 🎉 and some other emoji, it could be useful if there is a Quick Reactions that shows these emojis so user won't need to take too much time to find the emoji they want to react.

This change only related to the reaction emoji picker, and the commonly-used emojis are using the same ones as Element (and also GitHub, actually) used for Quick Reactions.

Element's Quick Reactions:

This patch: