Update: Convert template to JSX (fix #357)

[swashbuck]

Fix #357

Update

• Convert to template to JSX
• Media player wrapped in React.memo to prevent re-renders (MEJS manages its own DOM)
• Transcript toggle now model-driven (_isInlineTranscriptOpen) instead of jQuery DOM manipulation
• Completion aria label moved from JS DOM injection (setTranscriptCompletionAria) into template
• Removed events() method — click handlers passed as React onClick props

Fix

• Replaced deprecated $(window).resize() with Adapt.trigger('device:resize')
• Fixed media_poster → media__poster (BEM naming)
• Fixed controls='controls' → controls (JSX boolean convention)

[swashbuck]

Ready to review.