VE-1685: VisualEditor entry points in Venus

Do not mess up Venus edit section links by removing subscrption to DoEditSectionLink MediaWiki hook. It might look like it would hurt Oasis but it wouldn't - cause Oasis was overwriting output of that hook anyways in skins/oasis/modules/ContentDisplayController.class.php. The "bonus" of this change is that now we won't be doing that not necessary processing for Oasis.

https://wikia-inc.atlassian.net/browse/VE-1685