MCP Dynamic Tools

[mrchantey]

Currently types of content are hardcoded as ContentType and CrateMeta, being able to create tool descriptions based on a config file will allow us to move beyond the hardcoded types, and allow the user to define these in the beet.toml.

A good place to start might be checking out the MCP Rust SDK to see if dynamic tools are a thing.

Also I'm hoping to remove all toolbox and schemars macros, prefering bevy_reflect when we need to do schema stuff but have no idea if/how that would work.