Add setLogLevel()

This adds setLogLevel() to the lite SDK. Note that (at least for now) we don't validate API input, so we don't need to call the wrapper. Discussion on this is still pending.

Author: schmidt-sebastian

packages/firestore/lite/index.node.ts

@@ -38,6 +38,8 @@ export {
   serverTimestamp
 } from './src/api/field_value';
 
+export { setLogLevel } from '../src/util/log';
+
 export function registerFirestore(): void {
   _registerComponent(
     new Component(