Support long inputs and show progress

[dhdaines]

Does many things!

• Remove arbitrary file size limits
• Downsample audio to 8kHz for alignment
• Make align$ actually return an observable
• Redo the upload pipeline to use this observable
• Add stronger typing to various services (but not strong enough yet)
• Make the progress bar actually show progress!

Tested with the long Tusaalanga dialogue XML and MP3, does not crash!

[dhdaines]

NOTE! I doubt that it handles alignment errors correctly, it is likely to just hang forever. I will fix/test this ASAP.

[dhdaines]

In fact, it doesn't hang on alignment errors but gives this error (from the web component):

errorError: The alignment file could not be loaded

So I consider this acceptable for the moment...