Trajectory tab and 3D view updates.

[ChiCheng45]

Description of work

• Improved the trajectory loading performance. 42,592 atoms can be loaded in a few seconds.
• Added bonding to 3D view.
• Added unit cell to 3D view.
• Added method for faster access to atom database properties.
• Updated trajectory panel so that they are not reloaded on trajectory selection change.
• Optimized the build connectivity in MDANSE graph.

To test Load a few trajectories up in the trajectory tab and check 3D view is working correctly.