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

* Perform a better migration of Workspace Candidacies.
XWIKI-9516: Create a new Wiki API that replaces xwiki-platform-wiki-manager and xwiki-platform-workspace.

* Remove useless injects!
XWIKI-9516: Create a new Wiki API that replaces xwiki-platform-wiki-manager and xwiki-platform-workspace.

* Migration of Workspaces: Add the restoration of pages that was previously deleted by WorkspaceManager.Install.