Remove unused FormattingHelper import and instance

- Remove unused FormattingHelper import
- Remove unused format_helper instance variable
- Clean up unused code for better maintainability

This completes all code quality improvements.

MyTimeline.py

@@ -55,7 +55,6 @@ from gramps.gen.datehandler import get_date
 from gramps.gen.display.name import displayer as name_displayer
 from gramps.gui.views.navigationview import NavigationView
 from gramps.gui.views.bookmarks import FamilyBookmarks
-from gramps.gen.utils.libformatting import FormattingHelper
 
 _ = glocale.translation.sgettext
 
@@ -293,7 +292,6 @@ class MyTimelineView(NavigationView):
 
         self.dbstate = dbstate
         self.uistate = uistate
-        self.format_helper = FormattingHelper(self.dbstate, self.uistate)
 
         # Current family handle
         self.active_family_handle = None