command "list output" crashes when no output

[rcasteran]

Impacted version jarvis4se version: 1.1.3

Describe the bug When asking Jarvis to list the output of a function which has no output, it crashes.

To Reproduce Execute the following commands:

%%jarvis
with test
F1 is a function
list output F1

Expected behavior Jarvis must indicate that there is no output

Screenshots None

Desktop (please complete the following information):

• Browser: Chrome
• Browser version: 100.0.4896.75
• Java: JRE
• Java version: 1.8.0_291

[rcasteran]

Please implement the same behavior as in #25