XWIKI-9697: The Wiki (was: Workspaces) Search Suggestion is missing.

* Change the object number of the search engine for wikis to avoid conflicts when upgrading from an old XEM
* Add also a source that use Lucene instead of SolR.
Merge pull request #231 from gdelhumeau/XWIKI-9697

XWIKI-9697: The Wiki (was: Workspaces) Search Suggestion is missing
* Change the object number of the search engine for wikis to avoid conflicts when upgrading from an old XEM
* Add also a source that use Lucene instead of SolR.