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/FileUploader/Filename.svelte

@@ -1,42 +1,39 @@
 <script>
-  let className = undefined;
-  export { className as class };
-  export let iconDescription = '';
+  export let iconDescription = "";
   export let invalid = false;
-  export let status = 'uploading';
-  export let style = undefined;
-  export let tabindex = '0';
+  export let status = "uploading"; // "uploading" | "edit" | "complete"
 
-  import Close16 from 'carbon-icons-svelte/lib/Close16';
-  import CheckmarkFilled16 from 'carbon-icons-svelte/lib/CheckmarkFilled16';
-  import WarningFilled16 from 'carbon-icons-svelte/lib/WarningFilled16';
-  import { cx } from '../../lib';
-  import Loading from '../Loading';
+  import Close16 from "carbon-icons-svelte/lib/Close16";
+  import CheckmarkFilled16 from "carbon-icons-svelte/lib/CheckmarkFilled16";
+  import WarningFilled16 from "carbon-icons-svelte/lib/WarningFilled16";
+  import { Loading } from "../Loading";
 </script>
 
 {#if status === 'uploading'}
-  <Loading small description={iconDescription} withOverlay={false} class={className} {style} />
+  <Loading
+    description={iconDescription}
+    {...$$restProps}
+    small
+    withOverlay={false} />
 {/if}
 
 {#if status === 'edit'}
   {#if invalid}
-    <WarningFilled16 class={cx('--file-invalid')} />
+    <WarningFilled16 class="bx--file-invalid" />
   {/if}
   <Close16
-    class={cx('--file-close', className)}
     aria-label={iconDescription}
     title={iconDescription}
+    class="bx--file-close"
+    {...$$restProps}
     on:click
-    on:keydown
-    {tabindex}
-    {style} />
+    on:keydown />
 {/if}
 
 {#if status === 'complete'}
   <CheckmarkFilled16
-    class={cx('--file-complete', className)}
     aria-label={iconDescription}
     title={iconDescription}
-    {tabindex}
-    {style} />
+    class="bx--file-complete"
+    {...$$restProps} />
 {/if}