Add Workspace switcher to Referrals page

[gigxz]

Description

Issue: https://github.com/open-path/Green-River/issues/9204
Depends on Backend PR: greenriver/hmis-warehouse#6455
Opened against #1456 because it depends on referral refactor

• If workspaces are configured for referrals, render a "workspace switcher" that supports filtering all tabs by a project group.
• If no workspaces are configured, there is no change to the UI
• Components WorkspaceSelect and useWorkspaceSelector are implemented generically (not CE-specific) so they can be re-used if we introduce workspace switchers elsewhere, such as the User Dashboard.

See issue for how to test

Type of change

New feature

Checklist before requesting review

• I have performed a self-review of my code
• I have run the code that is being changed under ideal conditions, and it doesn't fail
• I have used Axe DevTools to scan for accessibility issues (or not applicable)
• My code includes comments and/or descriptive variable names to help other engineers understand the intent (or not applicable)
• I have updated the documentation (or not applicable)
• If it's not obvious how to test this change, I have provided testing instructions in this PR or the related issue

[martha]

Looks good to me. I don't think any of my comments are blocking. Thanks @gigxz ! Speedy work! 🚄

[martha]

I have a couple concerns about the dot + main color on the select component. I started typing up a comment here, but then decided I'll put my design comments in a thread over in Figma, for better separation of concerns :) Figma thread

Code-wise, if we do end up choosing to establish this pattern as part of our design language, I would prefer to put the custom styling in a thin presentational wrapper around GenericSelect. We could call it something like AccentedSelect, PrimaryColorSelect, BrandedSelect, etc. The dot and custom color could live there, and the component would pass the rest of its props down directly to the GenericSelect it renders.

[gigxz]

I believe the purpose is probably to bring some visual attention to the context switcher on the page and differentiate it from other "input"-type selectors.
Looks like your question is still open in Figma. For now, I just moved the adornment into its own component (within the same file) and added a note saying we can pull it out to another component or variant for re-use when needed.

Even if designs change, I think it'll be non-blocking for merge because nobody will see this functionality yet (not until we add any Workspace records)