add defaults to Button and ActionGroup components

packages/bbui/src/ActionGroup/ActionGroup.svelte

@@ -1,9 +1,9 @@
 <script>
     import "@spectrum-css/actiongroup/dist/index-vars.css"
-    export let vertical;
-    export let justified;
-    export let quiet;
-    export let compact;
+    export let vertical = false;
+    export let justified = false;
+    export let quiet = false;
+    export let compact = false;
 
     // Attaches a spectrum-ActionGroup-item class to buttons inside the div
     function group(element) {

packages/bbui/src/Button/Button.svelte

@@ -3,7 +3,11 @@
 
   export let disabled = false
   export let size = "M"
-  export let cta, primary, secondary, warning, overBackground
+  export let cta = false;
+  export let primary = false;
+  export let secondary = false;
+  export let warning = false
+  export let overBackground = false;
   export let quiet = false
   export let icon = undefined
   export let active = false