Refs #22373 Fix headers, adding back in some dependencies.

Framework/Muon/inc/MantidMuon/ApplyMuonDetectorsGrouping.h

@@ -2,7 +2,10 @@
 #define MANTID_MUON_APPLYMUONDETECTORSGROUPING_H_
 
 #include "MantidAPI/Algorithm.h"
+#include "MantidAPI/MatrixWorkspace.h"
+#include "MantidAPI/WorkspaceGroup.h"
 #include "MantidKernel/System.h"
+#include "MantidMuon/MuonAlgorithmHelper.h"
 
 using namespace Mantid::API;
 

Framework/Muon/inc/MantidMuon/MuonAlgorithmHelper.h

@@ -2,6 +2,8 @@
 #define MANTID_MUON_MUONALGORITHMHELPER_H_
 
 #include "MantidAPI/GroupingLoader.h"
+#include "MantidAPI/MatrixWorkspace.h"
+#include "MantidAPI/WorkspaceGroup.h"
 #include "MantidKernel/System.h"
 
 #include <string>