Workaround for adjacent annotations bug

Until this is fixed by Parsoid, this is a dirty hack that compares
HTML attributes on annotations, excluding data-parsoid. Obviously
we shouldn't have any parsoid specific code so this should be removed
as soon as it is fixed properly.

Bug: 48194
Change-Id: Ibb18b4f653c664e8ab7876498dc8395d878f7aaa
Merge "Workaround for adjacent annotations bug"