[dev-tool] check-node-versions fails when using --node-versions flag without --node-version

[maorleger]

When using only node-versions without node-version you end up with the trailing empty string here which causes downstream errors when building docker container names.

> options = { "node-versions": "12,13,14,15", "node-version": "" }
{ 'node-versions': '12,13,14,15', 'node-version': '' }
> [...new Set(options["node-versions"]?.split(",").concat(options["node-version"]))]
[ '12', '13', '14', '15', '' ]

Showing the errors as well, because it's a good hint to what's happening

[check-node-versions-samples] docker: Error response from daemon: Conflict. The container name "/12-container" is already in use by container "9e702026ecaa87a8c40a54735611d00b9f3f31fe6e251913687b520dfa2891c6". You have to remove (or rename) that container to be able to reuse that name.
See 'docker run --help'.
[check-node-versions-samples] Docker container 12-container encountered an error

[check-node-versions-samples] docker: Error response from daemon: Conflict. The container name "/12-container" is already in use by container "9e702026ecaa87a8c40a54735611d00b9f3f31fe6e251913687b520dfa2891c6". You have to remove (or rename) that container to be able to reuse that name.
See 'docker run --help'.
[check-node-versions-samples] Docker container 12-container encountered an error
[check-node-versions-samples] Started running the docker container 14-container
[check-node-versions-samples] Using node v14.17.3 to install dependencies

I think the fix is as easy as a conditional or an added filter to exclude empty strings but did not have time to test it