Add page_event_id to all successive events (#17738)

* Add `page_event_id` to all successive events

* Update events.js

* Break out event inits into functions so they don't break each other

* Update events.js

* Update events.js

* Update events.js

lib/schema-event.js

@@ -32,6 +32,11 @@ const context = {
       format: 'date-time',
       description: 'The time we created the event; please reference UTC.'
     },
+    page_event_id: {
+      type: 'string',
+      description: 'The id of the corresponding `page` event.',
+      format: 'uuid'
+    },
 
     // Content information
     path: {
@@ -132,8 +137,7 @@ const exitSchema = {
   additionalProperties: false,
   required: [
     'type',
-    'context',
-    'exit_page_id'
+    'context'
   ],
   properties: {
     context,
@@ -141,12 +145,6 @@ const exitSchema = {
       type: 'string',
       pattern: '^exit$'
     },
-    exit_page_id: {
-      type: 'string',
-      format: 'uuid',
-      description: 'The value of the corresponding `page` event.'
-      // id of the "page" event
-    },
     exit_first_paint: {
       type: 'number',
       minimum: 0.001,