feat: Refactor code structure and optimize performance across multiple modules

mobile-apps/staff-app/lib/features/earning/data/earning_qgl.dart

@@ -0,0 +1,79 @@
+const String _staffPaymentFields = '''
+id
+rate
+assignment {
+  clock_in
+  clock_out
+  start_at
+  end_at
+  break_in
+  break_out
+  position {
+    shift {
+      event {
+        name
+        date
+        business {
+          id
+          name
+          avatar
+        }
+      }
+    }
+    business_skill {
+      skill {
+        name
+      }
+    }
+  }
+}
+work_hours
+amount
+status
+paid_at
+created_at
+updated_at
+''';
+
+const String getWorkSummaryQuerySchema = '''
+query GetWorkSummary {
+  staff_work_summary {
+    weekly_hours
+    monthly_hours
+    weekly_earnings
+    monthly_earnings
+  }
+}
+''';
+
+const String getPaymentsQuerySchema = '''
+query GetStaffPayments (\$status: StaffPaymentStatusInput!, \$first: Int!, \$after: String) {
+  staff_payments(status: \$status, first: \$first, after: \$after) {
+    pageInfo {
+      hasNextPage
+    }  
+    edges {
+      node {
+        $_staffPaymentFields
+      }
+      cursor
+    }
+  }
+}
+''';
+
+const String confirmPaymentMutationSchema = '''
+mutation ConfirmStaffPayment (\$id: ID!) {
+  confirm_staff_payment(id: \$id) {
+    $_staffPaymentFields
+  }
+}
+''';
+
+const String declinePaymentMutationSchema = '''
+mutation DeclineStaffPayment (\$id: ID!, \$reason: String!, \$details: String) {
+  decline_staff_payment(id: \$id, reason: \$reason, details: \$details) {
+    $_staffPaymentFields
+  }
+}
+''';