Add dashboard url first promoter

[tspenov]

Changes

Added dashboardUrl to createPromoter and showPromoter.

     {
      showPromoter {
        email
        currentBalance
        earningsBalance
        paidBalance
        dashboardUrl
        promotions {
          refId
          referralLink
          promoCode
          visitorsCount
          leadsCount
          salesCount
          customersCount
          refundsCount
          cancellationsCount
          salesTotal
          refundsTotal
        }
      }
    }

Ticket

Checklist:

• I have performed a self-review of my own code
• I have made corresponding changes to the documentation
• I have tried to find clearer solution before commenting hard-to-understand parts of code
• I have added tests that prove my fix is effective or that my feature works