Add new component: image placeholder

[CuddleBunny]

What feature are you requesting?

Image placeholder component, similar to placeholder services such as https://placeholder.com/ but without a web request.

What would be the benefit of adding this feature?

Custom, fast, image placeholders without external dependencies.

What solution would be ideal for you?

Placeholder component, ideally a separate package so it can be used independent of fast, that may be styled with fast-design-system tokens. End user should be able to specify a height and width and possibly a label to describe image intent (logo, hero, figure, etc).

Attach screenshots or images add detail to your request:

This idea came about while discussing placeholder services in the project discord channel. I've created a quick prototype here: https://webcomponents.dev/edit/fpZQRNOHFSb8RIhJBVly with two possible implementations. One uses an SVG and the other creates an IMG by converting an SVG to base64.

[awentzel]

Additionally, this could be used in production for code examples, because it would be locally built into the bundle, not requested from 3rd party, thus solving subresource integrity concerns for security.

[chrisdholt]

Thanks @CuddleBunny - I think the primary question here is if this goes into the foundation bundle itself or whether this would be more worthwhile as part of an additional package or utility.

[CuddleBunny]

I think it makes sense as a standalone component that can optionally use the fast design properties whilst falling back to sensible defaults. This way it can be consumed without fast components if desired. Should a fast-contrib repo be set up for this purpose or should I just go ahead and roll my own repo?

[chrisdholt]

Given #5853, I think I'm going to close this. With that said, I'd love to see this as a utility library available on NPM perhaps :)

[CuddleBunny]

Given #5853, I think I'm going to close this. With that said, I'd love to see this as a utility library available on NPM perhaps :)

Can do, I've already made this and just need to spend the time to bundle it up separate some day.