This will allow us to refactor it, including adding class-level references to window.PageChooser and window.PageChooserModal as necessary, without dealing with the possibility of telepath/widgets.js being imported before the includes that define those.
This is necessary (according to the logic for adding Django form media objects together) whenever the JS adapter definition depends on anything defined in the widget JS - e.g. if foo-chooser.js defines `window.FooChooser`, and foo-chooser-telepath.js references that in the definition of FooChooserAdapter, then the only way to guarantee the correct ordering is with an explicit `['foo-chooser.js', 'foo-chooser-telepath.js']` media definition - adding two media objects does not guarantee this ordering.
This matches the implementation in components/ChooserWidget. This change breaks the tests that pass a jQuery collection object rather than a DOM element, but that was never valid in the first place as per https://docs.wagtail.org/en/stable/reference/streamfield/widget_api.html - fix the tests accordingly.
Previously, anything invoking the chooser modal needed to make its own call to ModalWorkflow, which meant it needed to import the corresponding 'onloadHandlers' dict, know the appropriate chosen response identifier to listen to, and know how to modify the chooser URL to pass parameters (if applicable). This would mean a lot of duplicated logic if there were multiple places where the modal is invoked.
Here we introduce a ChooserModal base class which encapsulates those details - a caller just needs to instantiate it with the base URL, and call `open` on it to open the modal (passing an options dict and a response callback).
- Revise 'redirect' from a string to a 'continue' boolean that defaults to false
- Use 'continue=true' for cases where we do not want to create a next param on submit that takes the user back to the current page
- Fixes #9815
- Fix any issues in files being ignored
- Fixed linting errors where appropriate
- Include some rules being ignored in the src/components folder
- Closes #8731
