Display the max number of users and people in the about page

[Grégoire_Miche2]

The help->about page gives some information related to the license.

But the volumetric information is missing:

• number of persons
• Number of users (Marketing, MSI)
• Number of RTP domains
• ...

Would be helpful if all this volumetric info was displayed there (or somewhere in the admin section, but it seems the most convenient in the about page)

-Greg