Implement FromPyObject for all types frequently created from dictionaries or strings

[smartgoo]

Consider adding custom FromPyObject impl for Python-exposed structs which are commonly created from Python dicts or strings.

https://pyo3.rs/v0.27.1/class.html#customizing-the-class

For example (note this code doesn't fully work, is just an example):

#[pyclass(name = "CovenantBinding", skip_from_py_object)]
pub struct PyCovenantBinding(CovenantBinding);

impl<'a, 'py> FromPyObject<'a, 'py> for PyCovenantBinding {
    type Error = PyErr;

    fn extract(ob: Borrowed<'_, 'py, PyAny>) -> PyResult<Self> {
        // Try native CovenantBinding instance first, then fall back to dict
        if let Ok(cb) = ob.cast::<Self>() {
            return Ok(cb.get().clone());
        }
        let dict = ob.cast::<PyDict>()?;
        Self::try_from(dict)
    }
}

This would also be beneficial for types that are frequently accepted in function signatures as a concrete type instance or string. PyNetworkId for example currently has as custom FromPyObject implementation. This allows functions that accept args of type PyNetworkId to receive an instance or a string.