Batch: Improve methods for creating jobs

[mnemitz]

• Define a JobInput type to handle three different input possibilities:
  • An instance of the File class, which implicitly gives a filename
  • An instance of Blob data, with an accompanying filename
  • A DataFetchConfig for server side data fetching
• Update signature of createJob and transcribe, passing entire JobConfig to API rather than destructuring fields.
• Add build step to format generated type declarations
• Update tests