ZEPPELIN501Notebooksearch

What is this PR for?

This PR has for goal to allow the user to search through the code in all the paragraphs and notebook names in all the notebooks

It add a simple 'search bar' to the nav-bar of Zeppelin WebApp, and an in-memory fulltext search index of paragraphs to the backend.

The search is pretty basic now, fine-tuning it for better search over all types of source code will be a subject of further work.

What type of PR is it?

Feature

Todos

• [x] - Fix typos :dancer: b853aa6


• [x] - fix js issue in js console 29da337


• [x] - update index on paragraph CRUD:


• [x] Read (initial work)


• [x] Create\Delete 825b266


• [x] Update e915a69


• [x] Delete paragraph


• [x] - add license to zeppelin-distribution/src/bin_license/LICENSE (backend for lucene, not sure about angular-resource as it is part of the AngularJS codebase, but will add just in case) c00b516


• [x] - add missing Apache headers ded9c3b 29da337


• [x] - fix CI (~~was failing RAT on zengine Too many files with unapproved license: 2~~, now flacky integration test AKA ZEPPELIN-510)


• [x] - index notebook names e80c3e5, 29da337


• [x] - make NotebookRepoSync.sync() package private again 5a18bc8


• [x] - NPE on persisting changes of existing notebook


• [x] - reduce log verbosity

Is there a relevant Jira issue?

https://issues.apache.org/jira/browse/ZEPPELIN-501

How should this be tested?

Outline the steps to test the PR here.

Screenshots (if appropriate)