Track various canvas states:
- Filtering an entity
- Transforming an entity
- Rasterizing an entity
- Compositing
- Busy (derived from all of the above)
Also track individual entity states:
- Locked
- Disabled
- All of type are hidden
- Has objects
- Interactable (derived from all of the above)
These states then gate various actions. For example:
- Cannot invoke while the canvas is busy.
- Cannot transform, filter, duplicate, or delete when the canvas is busy.
Tool interaction restrictions are not yet implemented.
Previously, canvas actions specific to an entity type only needed the id of that entity type. This allowed you to pass in the id of an entity of the wrong type.
All actions for a specific entity now take a full entity identifier, and the entity identifier type can be narrowed.
`selectEntity` and `selectEntityOrThrow` now need a full entity identifier, and narrow their return values to a specific entity type _if_ the entity identifier is narrowed.
The types for canvas entities are updated with optional type parameters for this purpose.
All reducers, actions and components have been updated.
- create a context for entity identifiers, massively simplifying UI for each entity int he list
- consolidate common redux actions
- remove now-unused code
