fixup! #44: Add DictionaryThriftStorage for using Identifier to add dictionaries

- Cleanup - add return types for DictionaryThriftStorage functions
#44: Introduce StoreUtil for creating Store from URI
#44: Introduce StorePath for conveniently passing around store + path
fixup! #44: Add DictionaryThriftStorage for using Identifier to add dictionaries

- Use StorePath
fixup! #44: Always use the latest dictionary from the repository

- Use StorePath