Use Town as plain Lua table

[ranisalt]

Pull Request Prelude

• [x] I have followed proper The Forgotten Server code styling.
• [x] I have read and understood the contribution guidelines before making this PR.
• [x] I am aware that this PR may be closed if the above-mentioned criteria are not fulfilled.

Changes Proposed

The Town metatable cannot be used to mutate towns, so it can be pushed as a table for a lighterweight implementation and to cleanup some functions in luascript