fix: display issue for quota

- DRY up `LogsTable.js` codebase
- Fix formatting in `LogsTable.js`
- Display 'free' for a 0 quota instead of empty string

web/default/src/helpers/render.js

@@ -38,6 +38,10 @@ export function renderNumber(num) {
 }
 
 export function renderQuota(quota, digits = 2) {
+  if (quota === 0) {
+    return 'free';
+  }
+
   let quotaPerUnit = localStorage.getItem('quota_per_unit');
   let displayInCurrency = localStorage.getItem('display_in_currency');
   quotaPerUnit = parseFloat(quotaPerUnit);
@@ -55,4 +59,4 @@ export function renderQuotaWithPrompt(quota, digits) {
     return `（等价金额：${renderQuota(quota, digits)}）`;
   }
   return '';
-}
+}