Expand styling capabilities to not assume :host container

[bheston]

Pull Request

Description

Much of the styling generation logic assumes the styles are in the context of a custom element. The Adaptive UI styling generation also works really well for other component frameworks and plain html if unique class names are used.

This PR removes the assumption that the containing element is :host and better enables other scenarios.

Issues

Related to #83

Reviewer Notes

Renamed a few occurrences of host to context. I was specifically avoiding words with meaning in css like root, host, and scope.

Test Plan

Tested in Storybook

Checklist

General

• I have included a change request file using $ npm run change
• I have added tests for my changes.
• I have tested my changes.
• I have updated the project documentation to reflect my changes.
• I have read the CONTRIBUTING documentation for this project.