Rate Limit API Calls

[nik-dange]

Info

Partially closes [#391].

Description

We're introducing rate limiting to prevent features like Express Checkin from being abused, since it's an unauthenticated route tied to SendGrid.

Changes

• Created new Rate Limiting Middleware
• TODO: add specific routes and config limits

Type of Change

• Patch (non-breaking change/bugfix)
• Minor (non-breaking change which adds functionality)
• Major (fix or feature that would cause existing functionality to not work as
  expected)
• Documentation (A change to a README/description)
• Continuous Integration/DevOps Change (Related to deployment steps, continuous integration
  workflows, linting, etc.)
• Other: (Fill In)

If you've selected Patch, Minor, or Major as your change type, make sure to bump the version before merging in package.json!

Testing

I have tested that my changes fully resolve the linked issue ...

• locally.
• on the testing API/testing database.
• with appropriate Postman routes. Screenshots are included below.

Checklist

• I have performed a self-review of my own code.
• I have followed the style guidelines of this project.
• I have appropriately edited the API version in the package.json file.
• My changes produce no new warnings.

Screenshots

Please include a screenshot of your Postman testing passing successfully.

TODO

[github-actions]

Thanks for contributing!
If you've made changes to the API's functionality, please make sure to bump the package
version—see this guide to semantic versioning for details—and
document those changes as appropriate.

[nik-dange]

I think this is kinda ugly, is there a more modular/cleaner way to check this? Ideally, we're only checking this against the express checkin route

[nik-dange]

Also this is ugly as well, it feels weird adding this app.set here. I don't think there's a way with our routing-controllers package to have the app.set config set, but maybe there's other ideas out there

[dowhep]

Will take a look again after u implemented the decorators.