Create <Button> component and use it in <GroupV2JoinDialog>

ts/components/Button.stories.tsx

@@ -0,0 +1,59 @@
+// Copyright 2021 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import React from 'react';
+import { storiesOf } from '@storybook/react';
+import { action } from '@storybook/addon-actions';
+
+import { Button, ButtonVariant } from './Button';
+
+const story = storiesOf('Components/Button', module);
+
+story.add('Kitchen sink', () => (
+  <>
+    <p>
+      <Button onClick={action('onClick')} variant={ButtonVariant.Primary}>
+        Hello world
+      </Button>
+    </p>
+    <p>
+      <Button
+        onClick={action('onClick')}
+        variant={ButtonVariant.Primary}
+        disabled
+      >
+        Hello world
+      </Button>
+    </p>
+
+    <p>
+      <Button onClick={action('onClick')} variant={ButtonVariant.Secondary}>
+        Hello world
+      </Button>
+    </p>
+    <p>
+      <Button
+        onClick={action('onClick')}
+        variant={ButtonVariant.Secondary}
+        disabled
+      >
+        Hello world
+      </Button>
+    </p>
+
+    <p>
+      <Button onClick={action('onClick')} variant={ButtonVariant.Destructive}>
+        Hello world
+      </Button>
+    </p>
+    <p>
+      <Button
+        onClick={action('onClick')}
+        variant={ButtonVariant.Destructive}
+        disabled
+      >
+        Hello world
+      </Button>
+    </p>
+  </>
+));