[IDEA] Improve features

[VRAM-RAM]

Improve / add features

We could add features very simple to handle (only on frontend) but that would add something to ZetaNet visible for the users. For example :

• Emojis / reactions (only in Ts frontend)

• Markdown support for messages (only in Ts frontend)

• Replies (In Ts frontend + backend (new MessageKind)) e.g MessageKind::PublicReply { username: String, reply_to: String, text: String } )

• Mentions (like discord) : @Admin -> only in Ts frontend

• List of connected users

[VRAM-RAM]

Added markdown

Added safe markdown support in zetaclient with :

      <div
        dangerouslySetInnerHTML={{
          __html: DOMPurify.sanitize(Marked.parse(text)),
        }}
      />

[VRAM-RAM]

Added emojis (added emoji picker)

Created zetaclient/static/src/components/EmojiPickerPopover.tsx for adding an Emoji picker in Private Messages View and Public Messages View.

[VRAM-RAM]

Added 'avatar', real timestamps and compact sidebar