Support responsive Hero banner on top of page

[Metisweb]

Is your feature request related to a problem? Please describe.
The requested feature is not related to a problem but more like an enhancement and a really nice to have.

Current default behaviour:
The thumbnail of a page will be displayed after the page title, description, tags, publication date and read time, and social icons. The default width of the thumbnail is col-8.

Describe the solution you'd like
Implementing an option in addition to the default behaviour where the thumbnail of a page can be displayed at the very top of a page immediately below the navigation bar. When this new option is active, the page title, description, tags, publication date and read time and social icons will be displayed below the thumbnail.

Options for the width of the thumbnail:

1. stretch the thumbnail to the full page width e.g. col-12
2. default width (col-8, as it is right now)

Adjustment for the aspect ratio of the thumbnail.

The described option should work on a page-by-page basis for flexibility.

This thumbnail display behaviour could be set in the frontmatter of a page, e.g.

thumbnail:
position: top (or when blank, default behaviour)
full-width: yes (yes=stretch thumbnail to full-width, no or blank = default behaviour)
aspect-ratio: 21x9 (and other aspect ratio friends)

A really super duper solution would be to also add full hero banner functionality. But this could be considered later.