fix: correct formatCurrency calls defaulting to EUR on payments page

Fix misplaced parenthesis in Math.abs() call that caused formatCurrency
to receive no currency arg (defaulting to EUR), and remove extra arg
in foreign currency formatting.

src/routes/cospend/payments/+page.svelte

@@ -97,7 +97,7 @@
       return formatCurrency(payment.amount, 'CHF', 'de-CH');
     }
 
-    return `${formatCurrency(payment.originalAmount, payment.currency, 'CHF', 'de-CH')} ≈ ${formatCurrency(payment.amount, 'CHF', 'de-CH')}`;
+    return `${formatCurrency(payment.originalAmount, payment.currency, 'de-CH')} ≈ ${formatCurrency(payment.amount, 'CHF', 'de-CH')}`;
   }
 
   function formatDate(dateString) {
@@ -236,7 +236,7 @@
                         {#if split.amount > 0}
                           owes {formatCurrency(split.amount, 'CHF', 'de-CH')}
                         {:else if split.amount < 0}
-                          owed {formatCurrency(Math.abs(split.amount, 'CHF', 'de-CH'))}
+                          owed {formatCurrency(Math.abs(split.amount), 'CHF', 'de-CH')}
                         {:else}
                           owes {formatCurrency(split.amount, 'CHF', 'de-CH')}
                         {/if}