add ResultProj and OperationProj to golang api?

[davidraleigh]

// set the projection data for the operation to execute in
func (c *Unary) SetOperationProjectionData(projData *eplpbv1.ProjectionData) *Unary {
	if c.geometryRequest != nil {
		c.geometryRequest.OperationProj = projData
		if c.geometryRequest.ResultProj == nil {
			c.commonProjectionData = projData
		}
	} else {
		c.err = errors.New("SetOperationProjection called when no geometryRequest had been set")
	}

	return c
}

// set the projection data for the operation to execute in
func (c *Unary) SetOperationProjectionEPSG(epsg int32) *Unary {
	projData := &eplpbv1.ProjectionData{}
	projData.SetEpsg(epsg)
	return c.SetOperationProjectionData(projData)
}