Small modernization creation of a library in TAlignment

The goal of the library is to host AlignAlgorithm and its dependencies so that it can be used in python via cppyy. This will avoid going through the Detector Store for the output of the alignment process, which is not a proper solution and not even possible at all with DD4hep.

If you wonder why it's not "proper", this is because accessing the Detector store requires in principle to now which conditions to load, requiring in turn to know which event we are dealing with. Now at the end of the alignment process (finalize stage), we have no event and thus no access to the DetectorStore. Current implementation abuses the system by still going there and using "what is left", in a very non thread safe mode. But DD4hep's implementation of the interface is safe and thus won't let you access without a proper event.

Alignment/AlignTrTools/src/WriteAlignmentConditions.cpp

@@ -24,52 +24,16 @@
 class WriteAlignmentConditions : public GaudiAlgorithm {
 
 public:
-  /// constructer
-  WriteAlignmentConditions( const std::string& name, ISvcLocator* svcloc );
-
-  /// destructer
-  ~WriteAlignmentConditions();
-
-  /// initialize
-  StatusCode initialize() override;
-
-  // finalize
+  using GaudiAlgorithm::GaudiAlgorithm;
   StatusCode finalize() override;
-
-  /// empty execute
   StatusCode execute() override { return StatusCode::SUCCESS; }
 
 private:
-  ToolHandle<IWriteAlignmentConditionsTool> m_tool;
+  ToolHandle<IWriteAlignmentConditionsTool> m_tool{this, "Tool", "WriteAlignmentConditionsTool"};
 };
 
 DECLARE_COMPONENT( WriteAlignmentConditions )
 
-//--------------------------------------------------------------------
-//
-//  WriteAlignmentConditions : Prints out the full geometry tree
-//
-//--------------------------------------------------------------------
-
-WriteAlignmentConditions::WriteAlignmentConditions( const std::string& name, ISvcLocator* pSvcLocator )
-    : GaudiAlgorithm( name, pSvcLocator ), m_tool( "WriteAlignmentConditionsTool", this ) {
-  // constructer
-  declareProperty( "Tool", m_tool );
-}
-
-WriteAlignmentConditions::~WriteAlignmentConditions() {
-  // destructer
-}
-
-StatusCode WriteAlignmentConditions::initialize() {
-  StatusCode sc = GaudiAlgorithm::initialize();
-  sc            = m_tool.retrieve();
-  return sc;
-}
-
 StatusCode WriteAlignmentConditions::finalize() {
-  StatusCode sc = m_tool->write();
-  m_tool.release().ignore();
-  if ( sc.isSuccess() ) sc = GaudiAlgorithm::finalize();
-  return sc;
+  return m_tool->write().andThen( [&] { return GaudiAlgorithm::finalize(); } );
 }