WebHost: add a page to manage session cookie (#4173)

WebHostLib/session.py

@@ -0,0 +1,31 @@
+from uuid import uuid4, UUID
+
+from flask import session, render_template
+
+from WebHostLib import app
+
+
+@app.before_request
+def register_session():
+    session.permanent = True  # technically 31 days after the last visit
+    if not session.get("_id", None):
+        session["_id"] = uuid4()  # uniquely identify each session without needing a login
+
+
+@app.route('/session')
+def show_session():
+    return render_template(
+        "session.html",
+    )
+
+
+@app.route('/session/<string:_id>')
+def set_session(_id: str):
+    new_id: UUID = UUID(_id, version=4)
+    old_id: UUID = session["_id"]
+    if old_id != new_id:
+        session["_id"] = new_id
+    return render_template(
+        "session.html",
+        old_id=old_id,
+    )