Improvements to #78731: Changed the code in AddFeatureToMap so its independent of GXP's feature editor, so we can add a new feature editor as the new modification tool
Adds modification tool for #78731. The tool inherits GXP's feature editor but overrides functionality so only edition is supported and so it doesn't meddle with other selection-related tools.
Removed unused code, and other minor improvements.
Added feature edition tool to the edition toolbar for #78731.
Merge pull request #117 from luisromangz/8.5-SNAPSHOT-78731

Advances for #78731: Adds feature editor tool and improves feature adding.