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

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

* Run "yarn build:docs"

src/UIShell/GlobalHeader/HeaderNavItem.svelte

@@ -1,66 +0,0 @@
-<script>
-  /**
-   * Specify the `href` attribute
-   * @type {string}
-   */
-  export let href = undefined;
-
-  /**
-   * Specify the text
-   * @type {string}
-   */
-  export let text = undefined;
-
-  /** Set to `true` to select the item */
-  export let isSelected = false;
-
-  /** Obtain a reference to the HTML anchor element */
-  export let ref = null;
-
-  import { getContext, onMount } from "svelte";
-
-  const id = "ccs-" + Math.random().toString(36);
-  const ctx = getContext("HeaderNavMenu");
-
-  let selectedItemIds = [];
-
-  const unsubSelectedItems = ctx?.selectedItems.subscribe((_selectedItems) => {
-    selectedItemIds = Object.keys(_selectedItems);
-  });
-
-  $: ctx?.updateSelectedItems({ id, isSelected });
-
-  onMount(() => {
-    return () => {
-      if (unsubSelectedItems) unsubSelectedItems();
-    };
-  });
-</script>
-
-<li role="none">
-  <a
-    bind:this="{ref}"
-    role="menuitem"
-    tabindex="0"
-    href="{href}"
-    rel="{$$restProps.target === '_blank' ? 'noopener noreferrer' : undefined}"
-    class:bx--header__menu-item="{true}"
-    aria-current="{isSelected ? 'page' : undefined}"
-    {...$$restProps}
-    on:click
-    on:mouseover
-    on:mouseenter
-    on:mouseleave
-    on:keyup
-    on:keydown
-    on:focus
-    on:blur
-    on:blur="{() => {
-      if (selectedItemIds.indexOf(id) === selectedItemIds.length - 1) {
-        ctx?.closeMenu();
-      }
-    }}"
-  >
-    <span class:bx--text-truncate--end="{true}">{text}</span>
-  </a>
-</li>