refactor: use $$restProps API

- add ref prop for applicable components (#196)
- add slot to Content Switcher `Switch` component (#183)
- remove fillArray, css utilities

src/components/CopyButton/CopyButton.svelte

@@ -1,52 +1,16 @@
 <script>
-  let className = undefined;
-  export { className as class };
-  export let feedback = 'Copied!';
-  export let feedbackTimeout = 2000;
-  export let iconDescription = 'Copy to clipboard';
-  export let style = undefined;
+  export let iconDescription = "Copy to clipboard";
 
-  import { afterUpdate, onDestroy } from 'svelte';
-  import Copy16 from 'carbon-icons-svelte/lib/Copy16';
-  import { cx } from '../../lib';
-
-  let animation = undefined;
-  let timeoutId = undefined;
-
-  afterUpdate(() => {
-    if (animation === 'fade-in') {
-      timeoutId = window.setTimeout(() => {
-        animation = 'fade-out';
-      }, feedbackTimeout);
-    }
-  });
-
-  onDestroy(() => {
-    window.clearTimeout(timeoutId);
-    timeoutId = undefined;
-  });
+  import { Copy } from "../Copy";
+  import Copy16 from "carbon-icons-svelte/lib/Copy16";
 </script>
 
-<button
-  type="button"
-  tabindex="0"
+<Copy
+  class="bx--copy-btn"
   aria-label={iconDescription}
   title={iconDescription}
-  class={cx('--copy-btn', animation && '--copy-btn--animating', animation && `--copy-btn--${animation}`, animation === 'fade-in' && '--btn--copy__feedback--displayed', className)}
+  {...$$restProps}
   on:click
-  on:click={() => {
-    animation = 'fade-in';
-  }}
-  on:mouseover
-  on:mouseenter
-  on:mouseleave
-  on:animationend
-  on:animationend={({ animationName }) => {
-    if (animationName === 'hide-feedback') {
-      animation = undefined;
-    }
-  }}
-  {style}>
-  <span class={cx('--assistive-text', '--copy-btn__feedback')}>{feedback}</span>
-  <Copy16 class={cx('--snippet__icon')} />
-</button>
+  on:animationend>
+  <Copy16 class="bx--snippet__icon" />
+</Copy>