Implement ILIAS auth and crawl home page

This commit introduces the necessary machinery to authenticate with
ILIAS and crawl the home page.

It can't do much yet and just silently fetches the homepage.

PFERD/utils.py

@@ -4,6 +4,8 @@ import functools
 import getpass
 from typing import Any, Callable, Optional, TypeVar
 
+import bs4
+
 T = TypeVar("T")
 
 
@@ -23,6 +25,12 @@ async def ainput(prompt: str) -> str:
 async def agetpass(prompt: str) -> str:
     return await to_thread(lambda: getpass.getpass(prompt))
 
+def soupify(data: bytes) -> bs4.BeautifulSoup:
+    """
+    Parses HTML to a beautifulsoup object.
+    """
+
+    return bs4.BeautifulSoup(data, "html.parser")
 
 async def prompt_yes_no(query: str, default: Optional[bool]) -> bool:
     """