Allow to set default center of map on the field widget

Problem/Motivation

Thanks for this amazing module! Exactly how I expect a module should work by providing such an awesome UX!
Just missing some features and I'll be creating some tickets for them.

I would like to set the default center of the map on the field widget. This is for now not configurable.

Steps to reproduce

Try to set a default for the center of the map.

Proposed resolution

Allow to set the center of the map on the field widget.

Remaining tasks

Create MR.

User interface changes

The center of the map will change.

API changes

None.

Data model changes

A setting for the center of the map in the field widget.