bugfix/1306: remove empty entry from explainTypes json response

[JoernBerkefeld]

PR details

What changes did you make? (Give an overview)

• closes [BUG] filter empty shell in explainTypes #1306

Further details (optional)

...

Checklist

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• test scripts updated
• Wiki updated (if applicable)

[github-actions]

Coverage Report

Commit:9169c1d
Base: develop@fe5b975

Type	Base	This PR
Total Statements Coverage	66.47%	66.48%  (+0.01%)
Total Branches Coverage	66.75%	66.78%  (+0.03%)
Total Functions Coverage	76.8%	76.8%  (+0%)
Total Lines Coverage	66.47%	66.48%  (+0.01%)

Details (changed files):

File	Statements	Branches	Functions	Lines
lib/util/cli.js	38.9%	78.04%	25%	38.9%