Create basic inventory and item system

[wesker-albert]

• create item data and object models
• player can now drop and get items
• player now has an inventory
• items dropped in room can be seen during navigation, or using look
• did some sub-dir organization
• added .env.test config, and factories/tests now use it instead of .env
• added data model tests and factory
• some minor styling tweaks for existing messages

Closes #13

[github-actions]

Package	Line Rate	Branch Rate	Health
.	59%	40%	❌
actions	96%	75%	✔
actions.commands	29%	23%	❌
actions.scheduled	0%	0%	❌
events	60%	46%	➖
models.data	97%	100%	✔
models.object	100%	100%	✔
resources	100%	98%	✔
Summary	55% (578 / 1057)	46% (161 / 353)	❌