feat(Tracking): add is_ugc attribute to tracking types

### Overview

adds `is_ugc` attribute to click, visit, and impression event tracking types (for use in portal-app)

### PR Checklist

- [x] Related to JIRA ticket: [REACH-1686](https://codecademy.atlassian.net/browse/REACH-1686)
- [ ] I have run this code to verify it works
- [ ] This PR includes unit tests for the code change

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Author: christian-dinh

packages/tracking/src/events/types.ts

@@ -183,6 +183,7 @@ export type UserClickData = UserSharedData & {
   assessment_id?: string;
   container_slugs?: string[];
   search_id?: string;
+  is_ugc?: boolean;
 };
 
 /**
@@ -216,6 +217,7 @@ export type UserVisitData = UserSharedData & {
   story_slug?: string;
   unit?: string;
   lesson?: string;
+  is_ugc?: boolean;
 };
 
 export type UserImpressionData = {
@@ -227,6 +229,7 @@ export type UserImpressionData = {
   track_slug?: string;
   module_slug?: string;
   source_codebase?: string;
+  is_ugc?: boolean;
 };
 
 export type EventAnswerData = BaseEventData & {