Calling debug_on without an argument should use the default server

[apolopena]

Describe the bug

Calling debug_on without an argument results in the error:

Error: debug_on(): must have at least one argument
Usage: debug_on server-type [no-refresh]

Steps to reproduce

• Create a new workspace from this starter
• Run debug_on

Expected behavior

• The default server should be used.
• The user should be notified that the default server being used.