Function gen_bridge_wrapper_struct 

pub fn gen_bridge_wrapper_struct(
    spec: &TraitBridgeSpec<'_>,
    generator: &dyn TraitBridgeGenerator,
) -> String

Generate the wrapper struct holding the foreign object and cached fields.

Produces a struct like:

pub struct PythonOcrBackendBridge {
    inner: Py<PyAny>,
    cached_name: String,
}