Add options parsing for charmstore api v4

[hatched]

Fix for bug: https://bugs.launchpad.net/juju-gui/+bug/1416469

When the user drag & dropped a charm from the charmbrowser it wasn't requesting and storing any charm configuration options so when trying to export it would fail as the options object was empty.

[hatched]

To QA

Drag a charm to the canvas from the charmbrowser
Switch to the Machine View and autoplace the charm
Deploy & Confirm the changes
Click export and it should download the bundle yaml file.

[jujugui]

Test FAILed.
Refer to this link for build results (access rights to CI server needed):
http://ci.jujugui.org:8080//job/juju-gui/2356/
Test FAILed.

[huwshimi]

Looks good, thanks Jeff. QA OK 👍

[hatched]

Thanks @huwshimi

After a few tries CI passed: http://ci.jujugui.org:8080/job/juju-gui/2358/

[frankban]

👍 thank you!

[hatched]

Thanks for the reviews!

[jujugui]

Build failed: Attempt to land pull request failed
build url: http://ci.jujugui.org:8080/job/juju-gui-merge/821

[jujugui]

Status: merge request accepted. Url: http://ci.jujugui.org:8080/job/juju-gui-merge