Adding New Level: Lua Metatable hooks

[TheDarkThief]

Summary

Adding a new level demonstrating Lua metatables, and how a malicious actor can hook into them

Changes

Created a level where a user requests the client to populate a table, where a malicious actor gains remote code execution due to improper sanitation.

Task list

• [x] For workflow changes, I have verified the Actions workflows function as expected.
• [x] For content changes, I have reviewed the style guide.

[TheDarkThief]

I've made the requested changes, as well as switch to the Busted library making it easier to setup Github CI as well as make the error messages a bit clearer