Feature add defaults to channel preferences

• Adds the default channel lists for all data types.
• Style the default rows to make it clear that they are not editable.
• Make it so that the default rows cannot be overwritten by the scan channels.
• Update the documentation.

Handles part of #187 (closed).

sohstationviewer/view/db_config/db_config_dialog.py

@@ -220,7 +220,7 @@ class UiDBInfoDialog(OneWindowAtATimeDialog):
         self.setup_ui()
 
     def setup_ui(self):
-        self.setGeometry(100, 100, 900, 900)
+        self.setGeometry(100, 100, 1100, 700)
         main_layout = QtWidgets.QVBoxLayout()
         self.setLayout(main_layout)
 
@@ -439,6 +439,9 @@ class UiDBInfoDialog(OneWindowAtATimeDialog):
         )
         self.data_table_widget.verticalHeader().hide()
         self.data_table_widget.setColumnCount(self.total_col)
+        print(self.total_col, len(self.column_headers))
+        # Make the two last columns have an empty header.
+        self.column_headers.extend(['', ''])
         self.data_table_widget.setHorizontalHeaderLabels(self.column_headers)
         header = self.data_table_widget.horizontalHeader()
         header.setSectionResizeMode(QtWidgets.QHeaderView.ResizeMode.Stretch)