Add networking options for configuring listening ports

- Handle both internal (unauth) an external (auth) ports
    - Allow specifying binding IP in `ip:port` format
- Simplify the templating for `listen.gotmpl` and `base_path.gotmpl`
    - Combine nginx settings getters into a single script `get_nginx_settings.py`
- Replace port constants `5000` and `8971` in code with values from config
- Update `Network Configuration` section in the advanced documentation

Provides a solution for discussion #17761

web/public/locales/en/config/networking.json

@@ -2,12 +2,23 @@
   "label": "Networking configuration",
   "properties": {
     "ipv6": {
-      "label": "Network configuration",
+      "label": "IPv6 configuration",
       "properties": {
         "enabled": {
           "label": "Enable IPv6 for port 5000 and/or 8971"
         }
       }
+    },
+    "listen": {
+      "label": "Listening ports configuration",
+      "properties": {
+        "internal": {
+          "label": "Internal listening port for Frigate"
+        },
+        "external": {
+          "label": "External listening port for Frigate"
+        }
+      }
     }
   }
-}
+}