Add a `Position` field for the center of an object

[kabilar]

• [x] I agree to follow the Code of Conduct that this project adheres to.
• [x] I have searched the issue tracker for a feature request that matches the one I want to file, without success.

Hi drawio team, thanks for your work on this project.

Is your feature request related to a problem? Please describe.

• I would like to be able to adjust the location of objects according to their center value.

Describe the solution you'd like

• Add a Center field in the Position section:

Describe alternatives you've considered

• Manually align objects based on their Left positions and widths.

Additional context

• n/a