feat: Add HealthCheck binary for docker

[bohregard]

Simple program that can be invoked by the Dockerfile to determine the health of the container.

Originally I was going to add curl/wget to the Dockerfile, but I know that's excluded on purpose in the original aspnet:8.0 container due to additional security vulnerabilities that could be used. So instead I created a tiny program using .net to query the added health check within the main application.

Addresses #932

[Vyerni]

Any chance this can get merged @hargata?

Would be helpful to have a healthcheck

[hargata]

@Vyerni At this point, not likely, but we want to keep the PR open because we want to be able to reference this and credit the original author when/if we do add health checks in the future.

Here's some of the big challenges for adding Docker health checks:

• LubeLogger isn't just distributed as an image, but also baremetal executables for Windows/Linux, so adding a separate executable that is only beneficial when ran as a Docker image will result in future vestigial code because
• dotnet has a ticket for this specific issue, and there are some really good discussions in here regarding why there are no built-in provisions for healthchecks(including a potential move to OCI in the future where healthchecks are not supported)
• This implementation hardcodes http://localhost:8080 as the health check endpoint and cannot be easily modified by the user. This is problematic because while 8080 is the default port, LubeLogger actually allows users to change which port and endpoint the app listens on internally via the Server Settings Configurator.

Currently we are in a holding position to just wait and see what the future looks like. If this was a SaaS it would have been resolved a long time ago, but since it's self-hosted, what we add and remove in the project matters a lot because people will come to rely on it.

[Vyerni]

I understand where your coming from.

But on the other hand too, at the moment there's nothing really in the way of tooling within the current docker image to allow showing that the container is up and healthy.

Any chance we could get curl or wget included in the default image? We can at least check the webserver is online and responding to validate this.