CORS Support for API

[503Dev]

Is your feature request related to a problem? Please describe.
When attempting to access the api endpoints via http get with fetch or axios a CORS error is returned as it appears Flask CORS is not enabled.

Describe the solution you'd like
Enable Flask CORS for the api endpoints.

Describe alternatives you've considered
NA - From the client using the api provided by mariner there is no way to circumvent CORS.

Additional context
I am running mariner3d on a local pi zero. I have my own dashboard to aggregate multiple printers and use axios to grab api endpoints. I can easily access the api endpoint server side but using a react app or a browser app I get a CORS error due to cross-origin header not being sent by server. I believe the fix is to use Flask CORS however I am not sure how to edit the live install of mariner3d. I know where to edit the source but not sure how to edit the live install.