Empty transcription causes error for digitalpaperedit transcripts

[emettely]

Describe the bug

When the transcriptData is empty like so:

{
  words: [],
  paragraphs: []
}

it throws an error.

To Reproduce
Steps to reproduce the behavior:

1. Insert empty transcript data as above
2. see error

Expected behavior
Empty transcript shouldn't be considered an error.

Screenshots

Desktop (please complete the following information):

• OS: [e.g. iOS]
• Browser [e.g. chrome, safari]
• Version [e.g. 22]

Smartphone (please complete the following information):

• Device: [e.g. iPhone6]
• OS: [e.g. iOS8.1]
• Browser [e.g. stock browser, safari]
• Version [e.g. 22]

Additional context