Refactor and enhance type hints across multiple modules

- Updated the `from_tuple` method in `Prof` class to specify return type.
- Added type hints for various methods in `LehmannsClient`, `OpenAI`, `WebRequest`, and `ZoteroController` classes to improve code clarity and type safety.
- Modified `pdf_to_csv` function to return a string instead of a DataFrame.
- Enhanced error handling and type hints in `wordparser` and `xmlparser` modules.
- Removed unused UI file `Ui_medianadder.ts`.
- Improved the layout and structure of the `semesterapparat_ui` to enhance user experience.
- Updated file picker to support `.doc` files in addition to `.docx`.
- Added unique item handling in `Ui` class to prevent duplicates in apparat list.
- General code cleanup and consistency improvements across various files.

src/logic/semester.py

@@ -232,3 +232,17 @@ if __name__ == "__main__":
     # print("generate_missing:", [str(s) for s in chain])
 
     # Parsing demo ---------------------------------------------------------
+    examples = [
+        "SoSe 6",
+        "WiSe 6/7",
+        "WiSe 6",
+        "SoSe 23",
+        "WiSe 23/24",
+        "WiSe 24",
+        "WiSe 99/00",
+        "SoSe 00",
+        "WiSe 100/101",  # test large year
+    ]
+    for ex in examples:
+        parsed = Semester.from_string(ex)
+        print(f"'{ex}' → {parsed} ({parsed.year=}, {parsed.semester=})")