ui: fixed crash selecting rows on old PyQt versions

In PyQt < 5.15 isRowSelected() requires two arguments (row and parent).
Since 5.15, the parent argument is optional, and the default value is an
empty QModelIndex().

In order to support old PyQt versions (Ubuntu 20.x), we add always
the second argument.

- Misc: headers reorganization.

Author: gustavo-iniguez-goya

ui/opensnitch/customwidgets/generictableview.py

@@ -1,12 +1,16 @@
-from PyQt5.QtGui import QColor, QStandardItemModel, QStandardItem
-from PyQt5.QtSql import QSqlQueryModel, QSqlQuery, QSql
-from PyQt5.QtWidgets import QTableView, QAbstractSlider
-from PyQt5.QtCore import QItemSelectionRange, QItemSelectionModel, QItemSelection, pyqtSignal, QEvent, Qt
-import time
+from PyQt5.QtGui import QStandardItemModel
+from PyQt5.QtSql import QSqlQuery, QSql
+from PyQt5.QtWidgets import QTableView
+from PyQt5.QtCore import (
+    QItemSelectionRange,
+    QItemSelectionModel,
+    QItemSelection,
+    QModelIndex,
+    pyqtSignal,
+    QEvent,
+    Qt)
 import math
 
-from PyQt5.QtCore import QCoreApplication as QC
-
 class GenericTableModel(QStandardItemModel):
     rowCountChanged = pyqtSignal()
     beginViewPortRefresh = pyqtSignal()
@@ -302,7 +306,7 @@ def mouseMoveEvent(self, event):
             clickedItem = self.model().index(row, self.trackingCol)
             if clickedItem.data() == None:
                 return
-            self.handleMouseMoveEvent(row, clickedItem, self.selectionModel().isRowSelected(row))
+            self.handleMouseMoveEvent(row, clickedItem, self.selectionModel().isRowSelected(row, QModelIndex()))
 
         finally:
             # call upper implementation to select/deselect rows.