Revert "Post Comment uses an object"

This reverts commit 25fff35c32f45452b1aeeb07dc8fa8a68cf931b6.
Revert "Post Comment: move unserializing to cover all uses"

This reverts commit 30f023cc42d3499d5014e7f3bf5d3293d4d8af79.
Revert "Post Comment should unpack Attributes"

This reverts commit 9288b3f22c927c75a43eabec2b4f23776bc549b2.