[Super Admin/ Dashboard] implement new stats in dashboard

[teodoranegru]

Implement the following stats in the Dashboard section. The data below refers to the beneficiaries from all shelters.

Total beneficiaries all time

Total requests per status -> New, Referred, Pending, Accepted, Rejected, Obsolete, Duplicate

Total beneficiaries per nationality

Total beneficiaries per gender

Total beneficiaries per age group -> Infant (up to 2 years old), Early childhood (3 - 6 years old), Middle childhood (7 to 12 years old), Adolescents/Teens (13 to 17 years old), Young Adults (18 - 39), Middle-aged Adults (40 - 59), Older persons (+60 years old)

[andreiio]

Total beneficiaries per age group -> compute age group when stay added to beneficiary. Store on stay