Function split_qualified_name 

pub fn split_qualified_name<'a>(
    namespaces: &'a Map<String, Value>,
    qualified: &'a str,
) -> Option<(&'a str, &'a str)>

Splits a qualified wire name back into its tool name and namespace.

Returns None for a name the request never qualified, so an unrecognized call is left alone rather than attributed to the wrong namespace. The tool name may itself contain the separator, so the namespace is matched as a prefix rather than by splitting on it.