Play/Pause object motion

[nbbosco]

This pull request adds the ability to play and pause object motion in the 3D viewer, providing both a toolbar button and a keyboard shortcut (spacebar) for user control. It introduces state management for object motion, updates the UI to reflect motion status, and ensures proper communication with the backend when the motion state changes.

New Object Motion Controls:

• Added a ToggleMovementButton to the display toolbar, allowing users to play or pause object motion directly from the UI. The button visually reflects the current motion state and is only shown when motion is available. [1] [2] [3] [4]
• Implemented a spacebar keyboard shortcut to toggle object motion, updating both the UI and the backend accordingly. [1] [2]

State Management and Backend Communication:

• Introduced a motionState object in the store to track whether object motion is paused and whether motion is available.
• Created the objectMotionManager and related functions to handle object motion availability, state toggling, and backend notification.
• Updated message dispatch logic to respect the paused state, preventing object updates when motion is paused, and to handle new motion-related messages from the backend. [1] [2] [3] [4]