[Toaster] [version 2 review-request] fix banner after customimage package add

[Dave Lerner]

Branch: toaster-next
Defect: 9101
Summary: version2: toaster: fix banner after customimage package add

v1 vs v2 change: Removed patch  to views.py that will be addressed in a different manner for a different defect per review comments from Michael.

Test Setup
----------
Build core-image-sato in order to capture package dependencies for tests.
Create a new custom image based on core-image-minimal.
Test with the pacakge atk which has 3 unadded dependencies: libpcre, glib-2.0, and libffi.
Make certain that old orm_customimage_* tables are empty, no residuals from 
prior runs.

Test cases and expected results
-------------------------------
Verify that adding a package with unaddded dependencies will add the dependencies visually and in the build by:
    Click the 'add package' button for package atk.
    Click 'add package' in the popup modal dialog to add the 3 dependencies.
    Verify that all 4 packages, atk and 3 dependents, now show buttons with
        labels 'remove package' instead of 'add...'
    Build the image.
    Verify in the built image under packages that all 4 packages are added
        to the image using the right panel Packages and clicking each package.

Verify that adding a package with either 
- a package with dependency list already added or in the image, 
- or without dependency list 
correctly shows the addition of 1 package in the banner.
    Remove atk, then add it back atk. 
    Verify that banner says 
        "You have added <bold>1</bold> package to myimage : atk"
    Note: only 1 package because dependencies were not removed in previous
        step.