Fixed weird translation of strings related to "seek to live" and 'font', and weird usage of terms 'video' and 'audio'. Some refinement is made to improve existing translation as well.
Restore hidden label text for screen readers that describes what the button control does.
Renames the Duration Time language item to Duration.
Deprecate controlText_ property.
Fix a typo in translations-needed.md.
Add a space in the hidden label for live-display, so that it doesn't run together with the visible "LIVE" indication.
Fixes#5135