Add config to remove checks array if empty

[xstefank]

Originally asked for in #160 (comment).

@sklakegg, I created a separate issue for this.

[xstefank]

@sklalegg, can you please let me know if this interface - https://github.com/smallrye/smallrye-health/blob/main/api/src/main/java/io/smallrye/health/api/HealthContentFilter.java, sorry it's still not document since I didn't have time to do it.

But you can then do something in line of this - https://github.com/xstefank/quarkus-reproducers/blob/main/sr-health-remove-checks/src/main/java/org/acme/RemoveEmptyChecksArrayHealthContentFilter.java

But if this is a common use case, I will add a new config to include this out of the box.

[sklakegg]

Thanks @xstefank :)
I will give it a try!