Create an AppEntitiesHeader widget

- Create a library named EntityHeaderWidgets, it can contains
  other entity header wdigets in the future.
- Create a controller of AppEntitiesHeader,
  then user can initialize its view easily.

Test: visual, robotest
Change-Id: If11b3eba75334f66b72472b2139e0e7d93984dce
Fixes: 117621156