Configurable API URLs

[ericboucher]

Make it easier to configure the analysis API using two environment variables:
Setting REACT_APP_LOCAL to true (or any value really), will make the frontend point to localhost
Otherwise, you can set REACT_APP_API_URL directly to replace the default URL of prism-api.ovio.org.

For the alerts backend, you can now override the backend endpoint using the API_URL environment variable.

[github-actions]

Build succeeded and deployed at https://prism-559.surge.sh
(hash f4cffc5 deployed at 2023-11-16T16:26:37)

[laurentS]

Looks good to me. My only question is about whether there is a way to avoid having to set 2 variables to do local dev. In particular, hitting prism-api.ovio.org as a default implies not knowing which version of code is running there, meaning possible bugs due to version mismatches. My gut says the default should be localhost, but maybe I'm missing something...

[ericboucher]

Fair point. The API changes a lot less often than the frontend and usually "adds" functionalities so this allows most devs that only touch on the frontend to not have to think about the backend at all. We can always change this in the future if it becomes cumbersome