Modal info windows

[goldpbear]

Some use cases are emerging for a general-purpose modal information window. These include:

• Providing background and context during form data entry
• Providing background and context about map layers

In these situations users could benefit from additional information, but the constraints of the UI make it difficult to provide that information.

To address this, let's add a general-purpose modal information box to the base platform. This box would be simple: it would have a header, body text section, and close button. Modals would be triggered via a button or icon.

In the config, we could use a standard footprint to dial in modal settings, for example:

modal_info:
  header: _(Some header)
  body:
    - _(Body paragraph 1)
    - _(Body paragraph 2)

It would be up to the relevant component to decide where to render the modal trigger button, and in what style to render it. For example, a multi-stage input form could render a small trigger in the header for each stage. The layer panel could render a small "i" icon next to a layer name.