Fixes for image / file field JS error (content.toolbar not defined)

Signed-off-by: Elliot Condon <e@elliotcondon.com>
Fixed JS issue when field groups toggled by AJA would not appear

Signed-off-by: Elliot Condon <e@elliotcondon.com>
Make sure post_id is an int

Signed-off-by: Elliot Condon <e@elliotcondon.com>