[dashboard] import bundle/package form error messages are confusing and badly formatted

[Kirill Zaitsev]

To reproduce: Go to package definitions, import bundle, input package name to the bundle form and try to import it.

The message observed is not informative and clear.

https://www.dropbox.com/s/0eenwgklzae4cyq/Screenshot%202015-08-14%2019.21.27.png?dl=0

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/222859

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/222859
Committed: https://git.openstack.org/cgit/openstack/murano-dashboard/commit/?id=5241910c2c7214ca4c8dd4fae3f7a27e66b7a869
Submitter: Jenkins
Branch: master

commit 5241910c2c7214ca4c8dd4fae3f7a27e66b7a869
Author: zhu.rong <[e-mail]>
Date: Sat Sep 12 12:19:44 2015 +0800

    Improve error message for import bundle/package

    Go to package definitions, import bundle, input package name
    to the bundle form and try to import it.

    The message observed is not informative and clear.

    This patch improve this error message.

    Closes-Bug: #1485041
    Change-Id: Ib420e21c1f07feb167873139dbd463be52235cdd