formatter: initial and basic indentation/alignment and expose the formatting via the LSP (#2673)

common/util/string_util.cpp

@@ -121,4 +121,22 @@ std::string uuid() {
   }
   return res;
 }
+
+std::string repeat(size_t n, const std::string& str) {
+  if (n == 0 || str.empty())
+    return {};
+  if (n == 1)
+    return str;
+  const auto period = str.size();
+  if (period == 1)
+    return std::string(n, str.front());
+
+  std::string ret(str);
+  ret.reserve(period * n);
+  std::size_t m{2};
+  for (; m < n; m *= 2)
+    ret += ret;
+  ret.append(ret.c_str(), (n - (m / 2)) * period);
+  return ret;
+}
 }  // namespace str_util