XWIKI-8875: Add convenience hasVirtualWikis() method to api.XWiki
- Used it in a couple of places where isVirtualMode() was used
XWIKI-8822: Set virtual=1 by default and deprecate the virtual mode API
- Removed dead code
XWIKI-8822: Set virtual=1 by default and deprecate the virtual mode API
[minor] Added a note in wikiManager's API that when getting all the wikis, the main wiki might not be in the results if it does not have a descriptor created.