[feat] Create `<rh-background-image>`

[zeroedin]

Description

rh-background-image as an improvement on pf-background-image with more feature set and variants. Should allow the image to be used in a container as well as positioned within that container, as well as repeated. Maybe support use of multiple background images as well?

Suggested solution

Background image that could be placed like a standard <img> tag

Possible attributes:
src (string) - required - path to image
src-2x - path to 2x image
src-sm - path to sm image
src-sm-2x - path to sm 2x image
src-lg - path to lg image
// see pf-background-image for more about the src attributes usage as base example
repeat (boolean) - default: false - allow for repeating icons.

Example API

<rh-background-image src="/path/to/image.png" repeat></rh-background-image>

Additional context

Current open PR for <pf-background-image>

[markcaron]

CC: @jvanpelt