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/Form/Form.Story.svelte

@@ -1,18 +1,18 @@
 <script>
-  import Layout from '../../internal/ui/Layout.svelte';
-  import Checkbox from '../Checkbox';
-  import FormGroup from '../FormGroup';
-  import FileUploader from '../FileUploader';
-  import NumberInput from '../NumberInput';
-  import RadioButton from '../RadioButton';
-  import RadioButtonGroup from '../RadioButtonGroup';
-  import Button from '../Button';
-  import Search from '../Search';
-  import Select, { SelectItem } from '../Select';
-  import TextArea from '../TextArea';
-  import TextInput from '../TextInput';
-  import Toggle from '../Toggle';
-  import Form from './Form.svelte';
+  import Layout from "../../internal/ui/Layout.svelte";
+  import { Checkbox } from "../Checkbox";
+  import { FormGroup } from "../FormGroup";
+  import { FileUploader } from "../FileUploader";
+  import { NumberInput } from "../NumberInput";
+  import { RadioButton } from "../RadioButton";
+  import { RadioButtonGroup } from "../RadioButtonGroup";
+  import { Button } from "../Button";
+  import { Search } from "../Search";
+  import { Select, SelectItem } from "../Select";
+  import { TextArea } from "../TextArea";
+  import { TextInput } from "../TextInput";
+  import { Toggle } from "../Toggle";
+  import Form from "./Form.svelte";
 </script>
 
 <Layout>
@@ -25,42 +25,74 @@
       <Checkbox id="checkbox-1" labelText="Checkbox Label" />
       <Checkbox id="checkbox-2" labelText="Checkbox Label" disabled />
     </FormGroup>
-    <NumberInput id="number-input-1" label="Number Input" min={0} max={100} value={50} step={10} />
+    <NumberInput
+      id="number-input-1"
+      label="Number Input"
+      min={0}
+      max={100}
+      value={50}
+      step={10} />
     <FormGroup legendText="Toggle heading">
       <Toggle id="toggle-1" />
       <Toggle id="toggle-2" disabled />
     </FormGroup>
     <FormGroup legendText="File Uploader">
-      <FileUploader id="file-1" buttonLabel="Add files" labelDescription="Choose Files..." />
+      <FileUploader
+        id="file-1"
+        buttonLabel="Add files"
+        labelDescription="Choose Files..." />
     </FormGroup>
     <FormGroup legendText="Radio Button heading">
-      <RadioButtonGroup name="radio-button-group" defaultSelected="default-selected">
-        <RadioButton id="radio-1" value="standard" labelText="Standard Radio Button" />
+      <RadioButtonGroup
+        name="radio-button-group"
+        defaultSelected="default-selected">
+        <RadioButton
+          id="radio-1"
+          value="standard"
+          labelText="Standard Radio Button" />
         <RadioButton
           id="radio-2"
           value="default-selected"
           labelText="Default Selected Radio Button" />
-        <RadioButton id="radio-3" value="blue" labelText="Standard Radio Button" />
-        <RadioButton id="radio-4" value="disabled" labelText="Disabled Radio Button" disabled />
+        <RadioButton
+          id="radio-3"
+          value="blue"
+          labelText="Standard Radio Button" />
+        <RadioButton
+          id="radio-4"
+          value="disabled"
+          labelText="Disabled Radio Button"
+          disabled />
       </RadioButtonGroup>
     </FormGroup>
     <FormGroup legendText="Search">
       <Search id="search-1" labelText="Search" placeholder="Search" />
     </FormGroup>
     <Select id="select-1" defaultValue="placeholder-item">
-      <SelectItem disabled hidden value="placeholder-item" text="Choose an option" />
+      <SelectItem
+        disabled
+        hidden
+        value="placeholder-item"
+        text="Choose an option" />
       <SelectItem value="option-1" text="Option 1" />
       <SelectItem value="option-2" text="Option 2" />
       <SelectItem value="option-3" text="Option 3" />
     </Select>
-    <TextInput id="text-input-1" labelText="Text Input label" placeholder="Placeholder text" />
-    <TextInput id="text-input-2" type="password" labelText="Password" required />
+    <TextInput
+      id="text-input-1"
+      labelText="Text Input label"
+      placeholder="Placeholder text" />
+    <TextInput
+      id="text-input-2"
+      type="password"
+      labelText="Password"
+      required />
     <TextInput
       id="text-input-3"
       type="password"
       labelText="Password"
-      invalidText="Your password must be at least 6 characters as well as contain at least one
-      uppercase, one lowercase, and one number."
+      invalidText="Your password must be at least 6 characters as well as
+      contain at least one uppercase, one lowercase, and one number."
       required
       invalid />
     <TextArea