Unify workspace dropdowns; Update layouts (#458)

Unified Account and Workspace drop-downs; Layout updates, now header lives within the PageBody component; Sidebars now use floating variant

apps/e2e/tests/account/account.spec.ts

@@ -38,6 +38,8 @@ test.describe('Account Settings', () => {
 
     await Promise.all([request, response]);
 
+    await page.locator('[data-test="workspace-dropdown-trigger"]').click();
+
     await expect(account.getProfileName()).toHaveText(name);
   });