zeta2 inspector: Feedback box (#40732)

Adds a way to submit feedback about a zeta2 prediction from the
inspector. The telemetry event includes:
- project snapshot (git + unsaved buffer state)
- the full request and response
- user feedback kind and text 

Release Notes:

- N/A

assets/keymaps/default-linux.json

@@ -1290,5 +1290,13 @@
       "home": "settings_editor::FocusFirstNavEntry",
       "end": "settings_editor::FocusLastNavEntry"
     }
+  },
+  {
+    "context": "Zeta2Feedback > Editor",
+    "bindings": {
+      "enter": "editor::Newline",
+      "ctrl-enter up": "dev::Zeta2RatePredictionPositive",
+      "ctrl-enter down": "dev::Zeta2RatePredictionNegative"
+    }
   }
 ]