Function mentat_ffi::store_value_for_attribute

#[no_mangle]
pub unsafe extern "C" fn store_value_for_attribute(
    store: *mut Store, 
    entid: c_longlong, 
    attribute: *const c_char, 
    error: *mut ExternError
) -> *mut Binding

Returns a pointer to the the Binding associated with the attribute as :namespace/name for the given entid. If there is a value for that attribute on the entity with id entid then the value is returned. If there no value for that attribute on the entity with id entid but the attribute is value, then a null pointer is returned. If there is no Attribute in the Schema for the given attribute then a null pointer is returned and an error is stored in is returned in error,

Safety

Callers are responsible for managing the memory for the return value. A destructor typed_value_destroy is provided for releasing the memory for this pointer type.

TODO: list the types of error that can be caused by this function