Downconvert apiv4 bundle yaml to apiv3 format temporarily

[hatched]

Some apiv3 baskets still have multiple bundles in them. To combat this we are switching to using the apiv4 bundle yaml instead of the apiv3 bundle yaml and then wrapping it to make it appear to be the apiv3 format.

[hatched]

To QA

Test 1: http://localhost:8888/?deploy-target=bundle/rails-example-scalable-6
This should deploy a large complex bundle, not a simple 2 charm bundle.
Test 2: Click on a bundle in the charmbrowser and click the "deploy bundle" button
If it deployed then it's ok.
Test 3: Drag a bundle from the charmbrowser to the canvas
If it deployed then it's ok.

[makyo]

👍 QA okay, all bundles worked as expected.

[jujugui]

Test FAILed.
Refer to this link for build results (access rights to CI server needed):
http://ci.jujugui.org:8080//job/juju-gui/2386/
Test FAILed.

[hatched]

Spurious failure - these are becoming not so spurious

[huwshimi]

Looks good @hatched, I assume we've already updated the api request to v4 somewhere? 👍 No QA.

[hatched]

[jujugui]

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