This commit refactors all spatial Field Mappers to a common AbstractGeometryFieldMapper that implements shared parameter functionality (e.g., ignore_malformed, ignore_z_value) and provides a common framework for overriding type parsing, and building in xpack. Common shape functionality is implemented in a new AbstractShapeGeometryFieldMapper that is reused and overridden in GeoShapeFieldMapper, GeoShapeFieldMapperWithDocValues, LegacyGeoShapeFieldMapper, and ShapeFieldMapper. This abstraction provides a reusable foundation for adding new xpack features; such as coordinate reference system support.