.#23 #33 Improvements to the continuous annotations task UX

[Kenneth-Funes-TU-Delft]

• Video playback can be freely controlled while the there is not an active annotations process using the standard controls
• When the annotations start, the video playback resets to start and video controls are hidden.
• Now hiding the annotation tips when the annotation process stops
• Renamed the playbackStatus variable to convey that it is strongly linked to cam view change events.
• Removed the height prop from the ContentContainer. It was causing clipping issues
• Added a notification each time an annotation buffer is to be uploaded
• Moved the Modal "Can't find participant" dialog to the InstructionsSidebar
• Added a button to open the video tutorial in a separate tab
• Slight improvements on instructions text
• Added an argument to the ContinuousAnnotationTaskSpec to include the video tutorial url