Fix some IDE warnings, mostly around type safety on the Python side

server/handlers/pagetemplate.py

@@ -1,7 +1,10 @@
 from datetime import datetime
+from typing import Any
 
 import pytz
 import tornado
+from tornado import httputil
+from tornado.web import Application
 
 from core.config import ALLOW_SPOTTING, WEB_UI_OPTIONS, BASE_URL, SERVER_OWNER_CALLSIGN
 from core.constants import SOFTWARE_VERSION
@@ -11,6 +14,11 @@ from core.prometheus_metrics_handler import page_requests_counter
 class PageTemplateHandler(tornado.web.RequestHandler):
     """Handler for all HTML pages generated from templates"""
 
+    def __init__(self, application: "Application", request: httputil.HTTPServerRequest, **kwargs: Any):
+        self._template_name = None
+        self._web_server_metrics = None
+        super().__init__(application, request, **kwargs)
+
     def initialize(self, template_name, web_server_metrics):
         self._template_name = template_name
         self._web_server_metrics = web_server_metrics