CORE-4673 Updated message when saving invalid apps.

Refactored the ContainsErrorsOnHideDialog out of the AppsIntegrationPresenterImpl#isViewValid method and into the onBeforeHide method.
Added a separate dialog to display the new appContainsErrorsUnableToSave error message in the onSaveClicked method when the app is invalid.
CORE-4073: Moved app publish detection out of presenter.
Merge branch 'master' into STABLE