[I2-17] Added backend events API

[someretical]

New API endpoints:

• /events gets all events - to be used by the frontend (format listed below)
• /eventsWebhook endpoint used by the facebook webhook

Events format:

  public id: string;
  public title: string;
  public startTime: string;
  public endTime?: string;
  public location: string;
  public imageUrl: string;
  public link: string;

.env fields required - None of these should be exposed to the user

FB_WEBHOOK_VERIFY_TOKEN=
FB_EVENT_PAGE_ID=
FB_APP_ID=
FB_APP_SECRET=
FB_ACCESS_TOKEN=

[someretical]

i trolled too close to the sun, need to treat edit/create differently for the webhook listener