telemetry_events: Rename AssistantEvent to AssistantEventData (#28133)

This PR renames the `AssistantEvent` type to `AssistantEventData`, as it
no longer represents the event itself, just the data needed to construct
it.

Pulling out of https://github.com/zed-industries/zed/pull/25179.

Release Notes:

- N/A

crates/assistant_context_editor/src/context.rs

@@ -40,7 +40,7 @@ use std::{
     sync::Arc,
     time::{Duration, Instant},
 };
-use telemetry_events::{AssistantEvent, AssistantKind, AssistantPhase};
+use telemetry_events::{AssistantEventData, AssistantKind, AssistantPhase};
 use text::{BufferSnapshot, ToPoint};
 use ui::IconName;
 use util::{ResultExt, TryFutureExt, post_inc};
@@ -2498,7 +2498,7 @@ impl AssistantContext {
                         .language()
                         .map(|language| language.name());
                     report_assistant_event(
-                        AssistantEvent {
+                        AssistantEventData {
                             conversation_id: Some(this.id.0.clone()),
                             kind: AssistantKind::Panel,
                             phase: AssistantPhase::Response,