[reports] SimpleUI for viz Options

[jhmullen]

BlockSettings now has a child called VizSettings, which hooks up to a vizSettingsLogic key inside the viz content.

This object is used for storing a number of non d3plus settings, including:

• Tabs
• Mini vs Large
• Show/Hide Options Panel
• A custom title (separate from d3plus title)

There is currently a code editor with no guard rails, but there needs to be a "simple mode" where the above settings can be configured via UI.

Currently marked as low priority.