Provide IntoId trait for ID extraction

[JR-1991]

This PR introduces a QoL improvement trait called IntoID, which provides a standardized interface to extract relevant IDs for re-use in other parts of the code. The implementation now allows imp IntoId<...> types to either accept a raw ID string or a struct that has implemented the trait.

Example

// Create a compartment
    let compartment = model
        .build_compartment("cytosol")
        .name("cytosol")
        .unit(&ml.id())
        .build();

    // Create the ethanol species
    let ethanol = model
        .build_species("ethanol")
        .name("Ethanol")
        .compartment(&compartment) // We can now pass the entire instance or `compartment.id()`
        .initial_concentration(0.5)
        .unit(&mole.id())
        .has_only_substance_units(false)
        .build();