Revert "Implement new Editor Tabs UI (#IDEA-205489)"
Revert "Implement new Editor Tabs UI (#IDEA-205489)"

This reverts commit 13d36e7a

allotria/intellij-community,allotria/intellij-community,allotria/intellij-community,allotria/intellij-community,allotria/intellij-community,allotria/intellij-community,allotria/intellij-community,allotria/intellij-community,allotria/intellij-community,allotria/intellij-community,allotria/intellij-community,allotria/intellij-community,allotria/intellij-community