Add custom path option for healthcheck

[akuma12]

🚀 Feature

I'd like to be able to customize the path for the health check. Currently it defaults to /health, but I'd like to be able to add my own prefix to that, such as /my_service/health or any arbitrary value.

Motivation

We use a shared load balancer with path-based routing, so we have to use app-specific prefixes for our paths, such as /my_service_1/foo and /my_service_2/bar. Because of this, the health check path also needs to start with that prefix.

Pitch

Ideally I could add a healthcheck_path to the LitServer class initialization that would override the default path of /health.

Alternatives

Currently I'm getting around this by using server.app.add_api_route, and adding a custom healthcheck method to my LitAPI class. In this method, I've tried using Requests to make a GET request to the local /health endpoint, but that actually causes LitServe to exit, so at the moment it just returns an HTTP 200 response, and doesn't actually check the readiness of the server.

[ktrapeznikov]

Good feature to add