Build Express Route to Retrieve Event Data

**Overview**
Express route for portal to retrieve event data from firebase

**Details**
Currently, there only exists a _portalFunction_ to record and modify event data, but none to retrieve and read. This new express route will allow portal to retrieve and display event data in the firebase collections.

**Task List**
- [x] Add API route to express_portal.ts (must match **portal** route used for authentication)
- [ ] Build script function to retrieve event firebase data

**Additional context**
Note that this express route will be utilized by **portal** under _api/actions/event.ts_ to authorize this data retrieval.