This partialy reverts commit 07f57bd271.
Reason for revert: Article::newFromWikiPage causes an infinite loop
if 'ArticleFromTitle' hook handler ends up calling Action::getActionName.
The revert preserves new getArticle and getWikiPage methods since there
are a few extension changes merged dependent on these. Alternatively this partial revert, we could do a full revert with all the dependencies https://gerrit.wikimedia.org/r/c/mediawiki/core/+/585343
Bug: T249162
Change-Id: Ifa642a631caa2d265ee097711dc8727f84435ef0