[dex] show referrals count

[fredev]

in the referral tab of the portfolio page we need to view how many users have registered with the connected wallet

• Implement the GET /referrals call
• view the total referral counts for the three levels in the referral tab

[nicholas-aternum]

This task is resolved in Screen in https://github.com/lira-dao/ecosystem/issues/60 It's correct?