Fixes #47861.

This is a copy and paste of @jmartisk and @geoand work in Quarkus LangChain4j MCP Client, adapted to Quarkus OIDC

This PR is meant to offer a simple OIDC Provider Health Check for all OIDC and OAuth2 providers.

It pings the `discovery` endpoint, if it is available. Other endpoints, either MP Health compliant (to deal with ##47791) or other ones, for ex, some GitHub url, can be supported later as `quarkus.oidc.health-url`.

The JSON looks like this:

```json
{
"checks": [
{
"name": "OIDC Provider Health Check",
"status": "UP",
"data":

{ "tenant-id-refresh-token": "OK", "tenant-https": "OK", "tenant-listener": "OK", "tenant-split-tokens": "OK" }

}
]
}
```

Status will be `UP` if at least a single provider is `OK`, and `DOWN` otherwise.
Tenant statuses: `OK`, `Error`, `Disabled`, `Not Ready Yet`, `Unknown`.

This is only a start and it will definitely require some more tuning,but it is high time `quarkus-oidc` started supporting health checks, as well as telemetry.

I'll need to do a bit more testing and add more docs