Streamlining Entity Navigation in Annotation View

[sbatchelder]

Moving between different entity types in the annotation view for a given frame (eg Localization and frame States) requires going back and forth between the different entity panels. My users' workflow involves interacting with both Localizations and frame-level States both a significant amount and moving between the two panels is a source of slowdowns and potential error.

Proposed Solution: Make the different interfaces independently collapsible, such that two panel types can be open at the same time for easier UI interaction.