edit predictions: Onboarding funnel telemetry (#24237)

Release Notes:

- N/A

crates/zeta/src/onboarding_telemetry.rs

@@ -0,0 +1,9 @@
+#[macro_export]
+macro_rules! onboarding_event {
+    ($name:expr) => {
+        telemetry::event!($name, source = "Edit Prediction Onboarding");
+    };
+    ($name:expr, $($key:ident $(= $value:expr)?),+ $(,)?) => {
+        telemetry::event!($name, source = "Edit Prediction Onboarding", $($key $(= $value)?),+);
+    };
+}