Choose related pages using a modal workflow that can be aware of context.

### As a content author or administrator, I want a context-aware workflow for relating a page to another so that I can remember what kind of parent page I am choosing to relate child pages to.

**Is your feature request related to a problem? Please describe.**
https://github.com/cityofaustin/techstack/issues/3265 Is evidence that we are pushing the expected limits of expected usage of Wagtails PageChooserPanel.

**Describe the solution you'd like**
As a dev, I want the ability to choose a Wagtail Panel that I can easily provide the kind of context info we are looking for. As is, it isn't easy to extend the way we want (with custom titles based on what type of parent page is being considered). If this is a high value need, it might be better for us to design a reusable Panel for Wagtail, or otherwise revisit/re-think the way we choose related pages to feature.

**Describe alternatives you've considered**
I've tried all sorts of ways of doing this easily, which are mentioned in #3265.