List unnecessary assigned permission sets

[EricBURTE]

Is your feature request related to a problem? Please describe.
this issue is coming from your 2023 Dec 2nd's linkedin post :
In order to do some cleaning within my permission sets I would like to be able to differentiate among permission sets the ones that are useful, and the ones that are useless because not assigned or overlapping other already assigned permissions

Describe the solution you'd like
Up to you : See all permission sets without assignment to active users

Describe alternatives you've considered
Could be interesting to see overlapping permissions ;)

Additional context
Have a look at your SFDX plugin for more information :)