XWIKI-9516: Create a new Wiki API that replaces xwiki-platform-wiki-manager and xwiki-platform-workspace.

* Fix xwiki.extension.features
XWIKI-9516: Create a new Wiki API that replaces xwiki-platform-wiki-manager and xwiki-platform-workspace.

* Fix Wiki Candidate class
Merge pull request #196 from gdelhumeau/new-wiki-api

XWIKI-9516: Create a new Wiki API that replaces xwiki-platform-wiki-mana...