FLOE-119: another modification to metadata output

Changed the output of the metadata for the video. Moved the contentUrl to a meta tag, and added the meta tag for captions as an accessibilityFeature.
FLOE-131: Improved video metadata panel to not re-render itself at every modelChange.
FLOE-131: Fixed typo.
FLOE-131: Fixed the model binding on the protoTree for signLanguage.
Merge remote-tracking branch 'jobara/FLOE-119'

* jobara/FLOE-119:
  FLOE-119: another modification to metadata output
Merge remote-tracking branch 'cindyli/FLOE-131'

* cindyli/FLOE-131:
  FLOE-131: Fixed the model binding on the protoTree for signLanguage.
  FLOE-131: Fixed typo.
  FLOE-131: Improved video metadata panel to not re-render itself at every modelChange.