XWIKI-9738: Finalize migration from workspaces to the new wiki API.

* Create a module called xwiki-platform-wiki-workspaces-migrator.
* Remove object created by WorkspaceManager.Install in XWiki.SearchSuggestConfig
XWIKI-9738: Finalize migration from workspaces to the new wiki API.

* Create a module called xwiki-platform-wiki-workspaces-migrator.
* Remove object created by WorkspaceManager.Install in XWiki.SearchSuggestConfig
Merge pull request #233 from gdelhumeau/XWIKI-9738

XWIKI-9738: Finalize migration from workspaces to the new wiki API.