Add Tracking algorithm based on CKF

The pull request submitted is mainly about the tracking algorithm for the drift chamber, based on the geometry of the drift chamber with stereo wires. The main content is as follows:

1. The CKF algorithm package from BelleII, which includes the geometry, magnetic field, and input/output interfaces.
2. In the digitization of the drift chamber, a function for mixing uniform noise hits is added.
3. Add the Track finding algorithm based on CKF:DCTrackFinding.cpp.
4. The TruthTracker algorithm is updated to make it applicable to multi-tracks events.
5. Add some helper functions to get the geometry parameters.

And, the above code has all passed testing and exhibits good performance, meeting the requirements of CEPC for tracker part, including:

• Track efficiency: >99.5% for five single particles events.
• Momentum resolution：< 0.14% for muon with 10GeV

Detector/DetCRD/compact/CRD_common_v01/DC_Simple_v01_06.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<lccdd>
+
+  <info name="DriftChamber"
+    title="Test with Drift Chamber"
+    author="Tao Lin"
+    url="http://github.com/cepc/CEPCSW"
+    status="development"
+    version="v0">
+    <comment>Test with Drift Chamber</comment>
+  </info>
+
+  <define>
+
+    <constant name="DC_layer_number" value="66"/>
+    <constant name="Alpha" value="12*deg"/>
+    <constant name="Gas_radius_min" value="DC_rbegin+DC_inner_wall_thickness+DC_safe_distance"/>
+    <constant name="Gas_half_length" value="DC_half_length-DC_Endcap_dz-DC_safe_distance"/>
+    <constant name="Gas_length" value="Gas_half_length*2"/>
+    <constant name="DC_cell_width" value="18*mm"/>
+    <constant name="DC_inner_wall_radius_min" value="DC_rbegin"/>
+    <constant name="DC_inner_wall_radius_max" value="DC_rbegin+DC_inner_wall_thickness"/>
+    <constant name="DC_Endcap_rmin" value="DC_rbegin"/>
+    <constant name="DC_Endcap_rmax" value="DC_rend"/>
+
+    <constant name="DC_construct_wire" value="0"/>
+
+    <constant name="DC_layer_width" value="18*mm"/>
+
+  </define>
+
+  <limits>
+    <limitset name="DC_limits">
+      <limit name="step_length_max" particles="*" value="0.1" unit="mm" />
+    </limitset>
+  </limits>
+
+  <regions>
+    <region name="DriftChamberRegion">
+    </region>
+  </regions>
+
+  <detectors>
+    <detector id="DetID_DC" name="DriftChamber" type="DriftChamber" readout="DriftChamberHitsCollection" vis="DCVis" sensitive="true" limits="DC_limits">
+      <material name="Air"/>
+      <chamber id="0" material="GasHe_90Isob_10"/>
+      <side material="CarbonFiber"/>
+      <envelope vis="SeeThrough">
+        <shape type="BooleanShape" operation="Union" material="Air">
+          <shape type="Tube" rmin="DC_rbegin" rmax="DC_rend" dz="DC_half_length" />
+        </shape>
+      </envelope>
+
+      <module id="0" name="SignalWire" type="Tube" rmin="0*mm" rmax="0.01*mm" vis="RedVis">
+          <tubs name="W" type="Tube" rmin="0*mm" rmax="0.007*mm" material="Tungsten"/>
+          <tubs name="Au" type="Tube" rmin="0.007*mm" rmax="0.01*mm" material="Gold"/>
+      </module>
+
+      <module id="1" name="FieldWire" type="Tube" rmin="0*mm" rmax="0.03*mm" vis="GreenVis">
+          <tubs name="Al" type="Tube" rmin="0*mm" rmax="0.027*mm" material="Aluminum"/>
+          <tubs name="Ag" type="Tube" rmin="0.027*mm" rmax="0.03*mm" material="Silver"/>
+      </module>
+
+      <type_flags type="DetType_TRACKER + DetType_BARREL + DetType_GASEOUS + DetType_WIRE"/>
+      <!-- Use cm as unit if you want to use Pandora for reconstruction -->
+     <sensitive type="SimpleDriftChamber"/>
+     </detector>
+  </detectors>
+
+  <readouts>
+    <readout name="DriftChamberHitsCollection">
+      <segmentation type="GridDriftChamber" cell_size="DC_cell_width" detector_length="Gas_length" identifier_phi="cellID" layerID="layer" DC_rbegin="DC_rbegin" DC_rend="DC_rend" layer_width="DC_layer_width"/>
+
+
+      <id>system:5,layer:7:9,chamber:8,cellID:32:16</id>
+    </readout>
+  </readouts>
+
+</lccdd>