Allow Users to Specify Transcript Language in UI

[joncameron]

Description

There is a language field available for all supplemental files. A valid upload of a batch manifest will assign a language to the transcript by default; this should be able to be changed by users in the UI as well, since the supplemental files receive a language value but it may not be surfaced or may not be able to be changed in the application.

Done Looks Like

• Language form field added to Transcript edit form on the Manage Files page
• Language field behaves like the language field for caption files

Mockup