add route to list backups by site

src/backups.js

@@ -9,6 +9,7 @@ exports = module.exports = {
     update,
     setState,
     list,
+    listBySiteId,
     del,
 
     removePrivateFields,
@@ -195,6 +196,18 @@ async function list(page, perPage) {
     return results;
 }
 
+async function listBySiteId(siteId, page, perPage) {
+    assert.strictEqual(typeof siteId, 'string');
+    assert(typeof page === 'number' && page > 0);
+    assert(typeof perPage === 'number' && perPage > 0);
+
+    const results = await database.query(`SELECT ${BACKUPS_FIELDS} FROM backups WHERE siteId=? ORDER BY creationTime DESC LIMIT ?,?`, [ siteId, (page-1)*perPage, perPage ]);
+
+    results.forEach(function (result) { postProcess(result); });
+
+    return results;
+}
+
 async function del(id) {
     assert.strictEqual(typeof id, 'string');