Feature request: add the posibility to mark is_top_domain

[Pablohn26]

For each domain, there is a field named is_top_domain that is useful to avoid the insertion of sub-domains which belong to the same organization (i.e eu.example.com, us.example.com) (more info here),

When using "Add organization" in the frontend, there is no possibility to mark that option.

Would be useful to have that option to have better management over each domain and improve affiliation.