Implement CAPTCHA configuration estimation from avg, peak and

broke_my_site_traffic

The above metrics are sourced from the user and are stored in the
database to reuse at a later point in time when the mCaptcha instance's
admin changes suggested configuration.

I'm not sure if I want to recompute configuration every time the admin
updates suggested configurations or give the user an option to recompute
based on latest trends. If we recompute on every update, then should the
admin choose very high difficulty_factors then it would hold back the
user's visitors, which is not nice. But there should also be an option
to rerun estimates when older configuration no longer works properly.

sqlx-data.json

@@ -327,6 +327,22 @@
       ]
     }
   },
+  "61523f76efade451db9db38cf4c8092af7489a90cd4186e8d21eb1d8afafdf64": {
+    "query": "INSERT INTO mcaptcha_sitekey_user_provided_avg_traffic (\n        config_id,\n        avg_traffic,\n        peak_sustainable_traffic,\n        broke_my_site_traffic\n    ) VALUES ( \n         (SELECT config_id FROM mcaptcha_config \n          WHERE\n            key = ($1)\n          AND user_id = (SELECT ID FROM mcaptcha_users WHERE name = $2)\n         ), $3, $4, $5)",
+    "describe": {
+      "columns": [],
+      "parameters": {
+        "Left": [
+          "Text",
+          "Text",
+          "Int4",
+          "Int4",
+          "Int4"
+        ]
+      },
+      "nullable": []
+    }
+  },
   "717771c42737feb3f4ca13f2ab11361073ea17b55562a103f660149bf049c5c6": {
     "query": "SELECT difficulty_factor, visitor_threshold FROM mcaptcha_levels  WHERE\n            config_id = (\n                SELECT config_id FROM mcaptcha_config WHERE key = ($1)\n                AND user_id = (SELECT ID from mcaptcha_users WHERE name = $2)\n                )\n            ORDER BY difficulty_factor ASC;",
     "describe": {