EmojiInput refactoring

Closes #565 (closed)

• Reimplemented emoji-input as a component that enhances existing element via slots.
• Replaced copy-paste suggetsions in post status form
• Standardized format for autocomplete suggestions
• Switched to PopperJS popper-vue sucks
• Made suggestor async by default? for the next time
• Fixed bugs
• Rename emoji-input?