Refactor generation of color variant components to use a curated set of accessible colors for all states

[cjg89]

Description

Currently in Athena, we maintain an extensive list of color variables, as well as accessible text color combinations for components using those colors; however, those color combinations only pertain to default component states. We don't currently have a curated set of hover/focus/active state colors; those state colors tend to get generated/modified in mixins based on the default states' colors, meaning we have less control over what color combinations get generated for those states.

Some of our button variant states don't currently meet contrast requirements (e.g. the success/info/warning/danger outline buttons). Additionally, navbars don't use a color variant system at all; nav link colors are determined by a .navbar-light or .navbar-inverse class and whatever background utility class is added to the navbar.

We should create a list of designated color combinations for these alternate states, and refactor how these components get generated to ensure these color combinations are always used. This will likely mean a deprecation of the .navbar-light/.navbar-inverse classes for navbars, and shifting navbars to a color variant model (like buttons, badges, and cards).

Why it's Important

Unless manually overridden in Athena, most (interactive) components' hover/active states don't take into account color contrast requirements for accessibility.

Alternatives

n/a

Possible Implementation

See above

Additional context

n/a