Resolve "Subscriber&processor for landmark external detections"

Closes #478 (closed)

test/gtest_factor_relative_pose_3d_with_extrinsics_new.cpp

+//--------LICENSE_START--------
+//
+// Copyright (C) 2020,2021,2022 Institut de Robòtica i Informàtica Industrial, CSIC-UPC.
+// Authors: Joan Solà Ortega (jsola@iri.upc.edu)
+// All rights reserved.
+//
+// This file is part of WOLF
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+// at your option) any later version.
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+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+//--------LICENSE_END--------
     //--------LICENSE_START--------
     //
     // Copyright (C) 2020,2021,2022 Institut de Robòtica i Informàtica Industrial, CSIC-UPC.