Added trading support

[itzandroidtab]

Briefly describe what changes this PR introduces

Added trader support. Allows 2 users to trade items with eachother.

Support for:

• registering as a trader (lv 5 and 25 gold as the requirements)
• Multiple trade channels
• Chat in channels
• Chat during trade
• Cleanup when a user crashes in a trade
• 15 Gold trade fee
• Trading items

Basic support for:

• Putting a item in a empty slot. For now the server assumes every item only uses 1 slot so there might be overlapping items after a trade

Link to all issues that this PR solves

#199 #191

Relevant pictures/videos of the PR (optional)

https://github.com/Snaacky/dndserver/assets/9889898/5b53f547-e517-4625-abb2-6b19eef09d59

Checklist

• [ ] This change introduces new dependencies and I have included updated pyproject.toml and poetry.lock files.
• [x] This change requires database migrations and I have included an alembic migration.