Picabot

**Changelogs**
- **Feature:** Renamed function decorator from `on` to `event` for improved clarity and consistency.

**Bug Fixes**
- **Critical:** Corrected the import of `PicaMessage` by adding it to the `__init__` module, preventing import errors.
- **Minor:** Fixed a typo in the `sent_message` function name to `send_message`.

Changelog:
- **Raw Event:** Introduced a new event, "raw," to provide more flexibility for advanced users to directly process the underlying data without intermediaries.
- **Chat Message Data Wrapper:** Simplified the chat message data structure for new users by introducing a wrapper. This change necessitated updates to the "message" event and command functions to accommodate the new format.
- **Message Deletion Functionality:** Implemented the `PicaBot.delete_message` function, allowing the bot to delete messages under the condition that it's a moderator on the channel.

After 3 days of work, I present to everyone the first version of PicaBot.