Function load_modules 

pub fn load_modules(
    engine_state: &mut EngineState,
    store: &Store,
    modules: &HashMap<String, Integrity>,
) -> Result<(), Box<dyn Error + Send + Sync>>

Load modules from a topic->hash map into the engine’s VFS.

Each entry with topic X.Y.Z.nu is registered as: X/Y/Z/mod.nu

This allows scripts to write: use X/Y/Z