refactor(components): rewrite Button and ButtonLink components

Both:
* move styles to Sass placeholders

Button:
* add `isPressed` prop to Button
* add `isLoading` prop to Button (to differentiate state from
disabled)

ButtonLink:
* replace `external` prop with `isExternal` prop
* replace `href` prop with `to` prop

1 files changed, 7 insertions, 4 deletions

diff --git a/src/components/molecules/buttons/back-to-top.test.tsx b/src/components/molecules/buttons/back-to-top.test.tsx
index aaae3ef..a775841 100644
--- a/src/components/molecules/buttons/back-to-top.test.tsx
+++ b/src/components/molecules/buttons/back-to-top.test.tsx
@@ -1,11 +1,14 @@
 import { describe, expect, it } from '@jest/globals';
-import { render, screen } from '../../../../tests/utils';
+import { render, screen as rtlScreen } from '../../../../tests/utils';
 import { BackToTop } from './back-to-top';
 
 describe('BackToTop', () => {
   it('renders a BackToTop link', () => {
-    render(<BackToTop target="top" />);
-    expect(screen.getByRole('link')).toHaveAccessibleName('Back to top');
-    expect(screen.getByRole('link')).toHaveAttribute('href', '#top');
+    const id = 'top';
+
+    render(<BackToTop to={id} />);
+
+    expect(rtlScreen.getByRole('link')).toHaveAccessibleName('Back to top');
+    expect(rtlScreen.getByRole('link')).toHaveAttribute('href', `#${id}`);
   });
 });