Refactor several aspects of the ImageBanner:

- Extract a few new classes and methods from the previous code
- Directly encode ANSI rather than using `${}` properties
- Rework the scaling algorithm to prefer a fixed width
- Allow ImageBanner and TextBanner to be used together
- Rename several of the `banner.image` properties
- Add support for a left hand margin
- Add property meta-data

See gh-4647