DAR-343 | DAR-325 | Fixed redirections on userpages on corporate pages + extension cleanup

https://wikia-inc.atlassian.net/browse/DAR-325
https://wikia-inc.atlassian.net/browse/DAR-343

Changed CorporatePage extension into UserPageRedirects (also deleted not used part of this extension)
Removed LandingPage extension

Do not merge this pull request without https://github.com/Wikia/config/pull/141