CLI prints for outputs with null values

[levice14]

flow output case:

• output_01:

run flow from CLI - it prints only those flow outputs that have non null values - I would expect to see that I have outputs with null values

[tethryus]

@Bonczidai It would be more intuitive to have the outputs that have none null values separated from the rest that are null:

Something like:

• Executable outputs
• Null outputs

That way, in case you are expecting a value for a certain output, but the value returned in null, it will be easier to debug.