[SavedModel Fingerprinting] Introduce public API `tf.saved_model.expe…

…rimental.read_fingerprint(export_dir)` for reading a fingerprint given the file path (`export_dir`) of the SavedModel. Also, introduce new class `tf.saved_model.experimental.Fingerprint` which contains the fingerprint.

tensorflow/community#415
tensorflow/community#439

PiperOrigin-RevId: 493957227

tools/def_file_filter/symbols_pybind.txt

@@ -451,6 +451,7 @@ tensorflow::metrics::CheckpointSize
 [//tensorflow/cc/saved_model:fingerprinting_impl] # SavedModel Fingerprinting
 tensorflow::saved_model::fingerprinting::CreateFingerprintDef
 tensorflow::saved_model::fingerprinting::ReadSavedModelFingerprint
+tensorflow::saved_model::fingerprinting::MakeFingerprintMap
 
 
 [//tensorflow/compiler/jit:flags] # tfe