Hide Licence file section on package upload if empty

[rocklan]

Hides licence file section on package upload if empty.

Addresses #8547

[skofman1]

Thanks for the contribution @rocklan ! @lyndaidaii will work with you to get this reviewed and merged next week.

[zhhyu]

@skofman1 We may also consider polishing and enabling the rendering of markdown licenses (another great contribution from @rocklan) as we are stabilizing the new markdown parser:
#8278
#8277
maybe next sprint.