add dialog to manage highlighters

- no support for "no color"
- settings not saved to disk

bigtext.py

@@ -228,15 +228,19 @@ class InnerBigText(QWidget):
         if self.selection_highlight.start_byte != self.selection_highlight.end_byte:
             start = min(self.selection_highlight.start_byte, self.selection_highlight.end_byte)
             end = max(self.selection_highlight.start_byte, self.selection_highlight.end_byte)
+            bytes_human_readable = humanbytes(end - start)
             if end - start > (1024 ** 2) * 5:
                 you_sure = QMessageBox(
                     QMessageBox.Icon.Warning,
-                    self.tr("copy to clipboard"),
+                    self.tr("data selection"),
                     self.tr(
-                        "You are about to copy <b>%s</b> to the clipboard. Are you sure you want to do that?" % humanbytes(
-                            end - start)))
-                you_sure.setStandardButtons(QMessageBox.StandardButton.Yes | QMessageBox.StandardButton.No)
-                you_sure.setDefaultButton(QMessageBox.StandardButton.No)
+                        "You have selected <b>{0}</b> of data.").format(bytes_human_readable))
+                you_sure.setStandardButtons(QMessageBox.StandardButton.Cancel)
+                you_sure.addButton(QPushButton(self.tr("Copy {0} to Clipboard").format(bytes_human_readable)),
+                                   QMessageBox.ButtonRole.AcceptRole)
+                # TODO add save dialog
+                # you_sure.addButton(QPushButton(self.tr("Write to File")), QMessageBox.ButtonRole.YesRole)
+                you_sure.setDefaultButton(QMessageBox.StandardButton.Cancel)
                 result = you_sure.exec()
                 if result != QMessageBox.StandardButton.Yes:
                     # abort
@@ -267,7 +271,7 @@ class InnerBigText(QWidget):
         for l in self.lines:
             self.update_longest_line(len(l.line()))
 
-        highlighters = self.model.highlights
+        highlighters = self.model.highlighters()
         if self.model.get_query_highlight():
             highlighters = highlighters + [self.model.get_query_highlight()]
         highlighters = highlighters + [self.selection_highlight]  # selection highlight should be last