Add LuceneDoc directly to queue from LuceneIndexEditor

Currently the LuceneDoc is created from LuceneIndexEditor and added to LuceneDocumentHolder. From there its added to queue in LocalIndexObserver.

This can be improved by adding the document directly to DocumentQueue which would help in sync index where the document would get added to index by the time commit completes and reaches observer stage and LocalIndexObserver would not have to wait for indexing to complete.