Fix: add preliminary EcalEndcap

Detector/DetCRD/compact/CRD_common_v02/EcalEndcaps_Polyhedra_v01_01.xml

+<lccdd>
+  <define>
+    <constant name="Ecal_endcap_nlayers" value="ecalbarrel_layer"/>
+    <constant name="Ecal_cells_size" value="1*cm"/>
+    <!--constant name="Ecal_endcap_center_box_size" value="Ecal_endcap_inner_radius*2"/-->
+  </define>
+
+  <detectors>
+    <detector name="EcalEndcap" type="DD4hep_PolyhedraEndcapCalorimeter2" id="DetID_ECAL_ENDCAP" readout="EcalEndcapsCollection" vis="SeeThrough">
+      <type_flags type=" DetType_CALORIMETER + DetType_ENDCAP + DetType_ECAL " />
+
+      <dimensions numsides="Ecal_endcap_symmetry" rmin="Ecal_endcap_inner_radius" rmax="Ecal_endcap_outer_radius/cos(pi/Ecal_endcap_symmetry)"
+		  zmin="Ecal_endcap_zmin" />
+      <layer repeat="Ecal_endcap_nlayers" vis="SeeThrough">
+        <slice material="Air"             thickness="0.1*mm"               vis="SeeThrough" />
+        <slice material="G4_BGO"          thickness="10*mm"                vis="ECALVis" />
+        <slice material="Air"             thickness="0.2*mm"               vis="SeeThrough" />
+      </layer>
+    </detector>
+  </detectors>
+  
+  <readouts>
+    <readout name="EcalEndcapsCollection">
+      <segmentation type="CartesianGridXY" grid_size_x="Ecal_cells_size" grid_size_y="Ecal_cells_size" offset_x="Ecal_cells_size/2.0" offset_y="Ecal_cells_size/2.0" />
+      <!--id>system:5,module:3,stave:3,tower:5,layer:6,x:32:-16,y:-16</id-->
+      <id>system:5,side:2,module:3,stave:4,barrel:3,layer:6,slice:4,x:32:-16,y:-16</id>
+    </readout>
+  </readouts>
+  
+</lccdd>