Resolve a dot-path from a CborValue map.
e.g., resolve_path(value, “output.label”) traverses into nested maps.
Returns None if any segment is missing or the value is not a map at an intermediate step.
Empty path returns the value itself.
Build a nested CborValue map from a dot-path and a value.
e.g., set_path(“input.sentiment”, val) → Map { “input”: Map { “sentiment”: val } }
Empty path returns the value itself.