fix: Fixes form markup in text track settings

[mister-ben]

Description

Removes two messages in Chrome's issues tab relating to the text track settings

• A form field element should have an id or name attribute
• No label associated with a form field

Specific Changes proposed

Adds an id to each <select>, and sets the id as the for on associated <label>s.

Requirements Checklist

• Feature implemented / Bug fixed
• If necessary, more likely in a feature request than a bug fix
  • Change has been verified in an actual browser (Chrome, Firefox, IE)
  • Unit Tests updated or fixed
  • Docs/guides updated
  • Example created (starter template on JSBin)
• Reviewed by Two Core Contributors