Ability to pass the number of vertices in the execute method of OperatorBuffer.

[fabian-maysen]

The OGCGeometry buffer method returns a polygon for a point with a total of 97 coordinates, which allows us to have a very well defined polygon.

In some solutions, it is not necessary to have this resolution, so it would be necessary to be able to define this value. For a 100 meter buffer, it is not necessary to have 97 points.