Refresh generated outliner files
bugfix: rm duplicate outline rules
Spoofax/712
Code removed for now. It introduced another bug.
Revert "Code removed for now. It introduced another bug."

This reverts commit 492dc2d496f74bd16a16e5f3335923f41c325f2c.
Don't generate esv-based outliner anymore. Only generate an empty 'MyLang-Outliner.generated.esv' so that existing projects won't break.