Add health check API endpoints

[oneonestar]

Description

Add two new health check API endpoints: /trino-gateway/livez and /trino-gateway/readyz.

Additional context and related issues

/trino-gateway/livez always returns 200.
/trino-gateway/readyz returns 200 after the initial fetch from database and the first round of Trino cluster health check is completed. Otherwise, 503 will be returned.

Release notes

(x) Release notes are required, with the following suggested text:

* Added API health endpoints `/trino-gateway/livez` and `/trino-gateway/readyz` for monitoring liveness and readiness. ({issue}`issuenumber`)

[oneonestar]

Might need to bind ActiveClusterMonitor by default instead of injecting it in config.

[mosabua]

Have not really looked at the PR but I think we should agree on same names for those probes in Trino Gateway and Trino . What do you think are suitable URLs .. I think it could literally just be ready and live, or liveness and readiness .. or is there some standard that anyone is aware of?

@nineinchnick @martint @dain @electrum ?

[nineinchnick]

AFAIK Trino doesn't yet have endpoints dedicated for probes. The z suffix is a convention started at Google, widely adopted in Kubernetes apps. I'm ok with that, OTOH there's little chance we'll have conflicts with other endpoints.

[mosabua]

AFAIK Trino doesn't yet have endpoints dedicated for probes. The z suffix is a convention started at Google, widely adopted in Kubernetes apps. I'm ok with that, OTOH there's little chance we'll have conflicts with other endpoints.

Fair enough .. i saw the healthz in others but the two you created @oneonestar are better .. so lets run with that then.

[mosabua]

Mini nits for the docs, then good to go. Feel free to merge after fixing docs and testing locally

[oneonestar]

Local test looks good. Merging.

[mosabua]

Great.,., just make sure you squash commits...