Implement client facing theme

[Jipperism]

Starting work on implementing the client facing theme. Some questions, which we may have partially answered already but good to leave a written down version so it's available to everybody.

• What developer experience do we envision. From the way it's currently build, I don't think merely swapping out the theme/wrapping the component in a separate provider will be sufficient, as not all styling is done entirely through the theme (for example, in some composed components like Card.tsx. In our previous call, I think we decided to duplicate components as well as providing a raidguild/client theme. The downside of this approach is that developers will be required to import the correct components from eg @raidguild/design-system/rg and @raidguild/design-system/client. The upside is that we don't have to rewrite anything that's already there.
• Do we expect to see components from both sets side-by-side? In separate stories, under dropdowns for rg/client? It's pretty straightforward to show them side-by-side as the theme is currently only passed in through the global storybook parmas, which can also be defined on a story or component level (see the docs).

Pinging @scottrepreneur and @bitbeckers

[scottrepreneur]

From the way it's currently build, I don't think merely swapping out the theme/wrapping the component in a separate provider will be sufficient, as not all styling is done entirely through the theme (for example, in some composed components like Card.tsx.

Any styles that are currently handled in the component could ideally be moved to the theme. Streamlining to one set of components unless there is additional complexity there.

Do we expect to see components from both sets side-by-side?

Could be a separate storybook. Whatever solution seems easiest to maintain.

[Jipperism]

@scottrepreneur ended up implementing it as a theme switch. Going through the components to determine where styling still has to be moved into the theme, doesn't seem to be much.

Some open questions

• Do we expect every component to have a functioning version in both themes? For example, <Button /> with variant="gradientOutline".
• Do we want to be able to conditionally show stories, for only a specific theme?

Also, the Modal, Card, Dialog and Menu components do not seem to fully function on the raidguild theme, but this seems to already be an issue on main so it probably makes more sense to create separate issues for those.