Issues in add Trascripts widget in video editor

[ChrisChV]

• Can't type in the language I want in the dropdown; I have to scroll all the way down to the language to select it.
• No spinners shown while transcript uploads / downloads from Youtube are happening -- it just sits there looking like it's doing nothing.
  It also doesn't prevent me from clicking "Save", and so if an upload / replace / delete for a transcript fails, I don't know about it until I re-open the modal.
• When I import transcripts from YouTube, only one of the imported transcripts (English) shows up in the preview widget.
  I have to save, and the re-edit to see all languages for the imported transcripts.
• The "select a language then launch file upload control" behavior is non-intuitive, and may not be accessible either? I think these two components should split in two, so I can select my language / upload a file in whatever order I want to.
• The "Download" transcript menu item tries to send me to a new page. It should open in a new window (which closes after the download completes).