Implement file search

Clear found files list on clear button pressed

Make found files header bold

Enable clearing of search box with button click

Add tool tip to search box

Filter data sets on pressing Enter

Add function to filter directories

Closes #10 (closed)

sohstationviewer/view/ui/main_ui.py

@@ -96,11 +96,6 @@ class UIMainWindow(object):
         """
         self.clear_search_action: Optional[QAction] = None
         """
-        search_button: filter list of files based on content of
-            self.search_line_edit
-        """
-        self.search_button: Union[QPushButton, None] = None
-        """
         replot_button: reset plotting without re-loading data
         """
         self.replot_button: Union[QPushButton, None] = None