breaking(ui-shell): remove GlobalHeader, SideNav folders (#1223)

* breaking(ui-shell): remove GlobalHeader/SideNav folders

* Run "yarn build:docs"

src/UIShell/HeaderActionLink.svelte

@@ -0,0 +1,42 @@
+<script>
+  /** Set to `true` to use the active state */
+  export let linkIsActive = false;
+
+  /**
+   * Specify the `href` attribute
+   * @type {string}
+   */
+  export let href = undefined;
+
+  /**
+   * Specify the icon to render
+   * @type {typeof import("svelte").SvelteComponent}
+   */
+  export let icon = undefined;
+
+  /** Obtain a reference to the HTML anchor element */
+  export let ref = null;
+</script>
+
+<a
+  bind:this="{ref}"
+  class:bx--header__action="{true}"
+  class:bx--header__action--active="{linkIsActive}"
+  href="{href}"
+  rel="{$$restProps.target === '_blank' ? 'noopener noreferrer' : undefined}"
+  {...$$restProps}
+>
+  <slot name="icon">
+    <svelte:component this="{icon}" />
+  </slot>
+</a>
+
+<style>
+  .bx--header__action {
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    /** Hot fix to align icon with `HeaderAction` */
+    padding-bottom: 2px;
+  }
+</style>