UI sending websocket interface tags in a dictionary

[Lee Trager]

MAAS has the ability to add a tag to the interface using the API. This information is sent over the websocket although it is not currently displayed in the UI. Tags are sent as a list however the UI is returning them as a dictionary when modifying an interface. This causes the InterfaceForm to raise the exception "'dict' object has no attribute 'split'" and the interface is not changed.

Tags are sent from the region to the UI
['tag-1', 'tag-2', 'tag-3']

Tags are incorrectly sent from the UI to the region as
[{'text': 'tag-1'}, {'text': 'tag-2'}, {'text': 'tag-3'}]

Reproduction 1:
Run MAAS with sampledata and try to edit an interface

Reproduction 2:
1. In a live environment add a tag
   maas $PROFILE interface add-tag $SYSTEM_ID $INTERFACE_ID tag=foo
2. Try to edit the interface in the UI