Move NotifyPropertyChanged into doctrine/persistence

[Majkl578]

NotifyPropertyChanged + PropertyChangedListener should be moved to doctrine/persistence.
Namespace will stay untouched so this change won't be a BC break.

Once done, release:

• doctrine/persistence 1.1.0 with bumped conflicts to doctrine/common <2.10@dev
• doctrine/common 2.10.0 with bumped require todoctrine/persistence ^1.1

One of the last pieces for #826.