app - stitching: set the stitching output as a full path relative to the current working directory

close #1244

# Conflicts:
#	src/tomwer/app/stitching/common.py

# Conflicts:
#	src/tomwer/app/stitching/common.py

# Conflicts:
#	src/tomwer/app/stitching/common.py
#	src/tomwer/gui/utils/inputwidget.py

src/tomwer/gui/utils/inputwidget.py

@@ -437,7 +437,13 @@ class OutputVolumeDefinition(qt.QWidget):
         # output file or folder
         self._outputFileLabel = qt.QLabel("", self)
         self.layout().addWidget(self._outputFileLabel, 1, 0, 1, 1)
-        self._outputFileQLE = QLFileSystem("", parent=None)
+        self._outputFileQLE = QLFileSystem(
+            os.path.join(
+                os.getcwd(),
+                "stitched_volume.hdf5",
+            ),
+            parent=None,
+        )
         self.layout().addWidget(self._outputFileQLE, 1, 1, 1, 1)
         self._selectPB = qt.QPushButton("select", self)
         self.layout().addWidget(self._selectPB, 1, 2, 1, 1)