refactor: add prepareFilterQuery to utils (#2219)

* refactor: add `prepareFilterQuery` to utils
factored out the preparation of the url params for a paginated table and its requests.
usermanager will also use that.

lnbits/static/js/base.js

@@ -130,8 +130,7 @@ window.LNbits = {
         }
       )
     },
-    getPayments: function (wallet, query) {
-      const params = new URLSearchParams(query)
+    getPayments: function (wallet, params) {
       return this.request(
         'get',
         '/api/v1/payments/paginated?' + params,
@@ -366,6 +365,24 @@ window.LNbits = {
         return data
       }
     },
+    prepareFilterQuery(tableConfig, props) {
+      if (props) {
+        tableConfig.pagination = props.pagination
+      }
+      let pagination = tableConfig.pagination
+      tableConfig.loading = true
+      const query = {
+        limit: pagination.rowsPerPage,
+        offset: (pagination.page - 1) * pagination.rowsPerPage,
+        sortby: pagination.sortBy ?? '',
+        direction: pagination.descending ? 'desc' : 'asc',
+        ...tableConfig.filter
+      }
+      if (tableConfig.search) {
+        query.search = tableConfig.search
+      }
+      return new URLSearchParams(query)
+    },
     exportCSV: function (columns, data, fileName) {
       var wrapCsvValue = function (val, formatFn) {
         var formatted = formatFn !== void 0 ? formatFn(val) : val