Refactor UI imports and clean up unused code

- Removed unnecessary imports from various UI files to streamline the codebase.
- Deleted the unused documentation viewer implementation in `documentationview.py`.
- Cleaned up imports in `files.py` by removing `LOG_DIR` as it was not used.
- Removed the temporary script `temp.py` as it was no longer needed.

src/ui/dialogs/confirm_extend_ui.py

@@ -6,7 +6,7 @@
 # run again.  Do not edit this file unless you know what you are doing.
 
 
-from PySide6 import QtCore, QtGui, QtWidgets
+from PySide6 import QtCore, QtWidgets
 
 
 class Ui_extend_confirm(object):