Adding mapProvider config parameter to UI

[rabii]

The system currently allow to implement a custom map provider which really great. However, when implementing the custom provider the system by default display google as it is set to be a default mapProvider on the default config file. It would be great if that parameter is exposed to the user (admin) to change the provider from the UI.

Thanks

[yuri]

I will think about it.

Note that your PR has changed \r\n => \n.

[rabii]

Thanks Yuri

[item]

Maybe idea : https://github.com/geocoder-php/Geoc...ster/README.md
like flysystem provider