feat(popover): add closeOnOutsideClick prop

src/Popover/Popover.svelte

@@ -2,6 +2,9 @@
   /** Set to `true` to display the popover */
   export let open = false;
 
+  /** Set to `true` to close the popover on an outside click */
+  export let closeOnOutsideClick = false;
+
   /** Set to `true` render a caret */
   export let caret = false;
 
@@ -19,9 +22,26 @@
 
   /** Set to `true` to use a relative position */
   export let relative = false;
+
+  import { createEventDispatcher } from "svelte";
+
+  const dispatch = createEventDispatcher();
+
+  let ref = null;
 </script>
 
+<svelte:window
+  on:click="{(e) => {
+    if (!open) return;
+    if (e.target.contains(ref)) {
+      dispatch('click:outside');
+      if (closeOnOutsideClick) open = false;
+    }
+  }}"
+/>
+
 <div
+  bind:this="{ref}"
   class:bx--popover="{true}"
   class:bx--popover--caret="{caret}"
   class:bx--popover--light="{light}"