Material: include some more required header files

as otherwise the parser of the clang code model raises a lot of error messages

src/Mod/Material/App/ModelUuids.h

@@ -22,6 +22,8 @@
 #ifndef MATERIAL_MODELUUIDS_H
 #define MATERIAL_MODELUUIDS_H
 
+#include <QString>
+
 namespace Materials
 {
 

src/Mod/Material/App/trim.h

@@ -22,6 +22,7 @@
 #ifndef MATERIAL_TRIM_H
 #define MATERIAL_TRIM_H
 
+#include <algorithm>
 #include <string>
 
 namespace Materials