Set default getOptionIcon prop in core Picker to avoid crash

packages/bbui/src/Form/Core/Picker.svelte

@@ -18,7 +18,7 @@
   export let onSelectOption = () => {}
   export let getOptionLabel = option => option
   export let getOptionValue = option => option
-  export let getOptionIcon = null
+  export let getOptionIcon = () => null
   export let open = false
   export let readonly = false
   export let quiet = false
@@ -45,7 +45,7 @@
 >
   {#if fieldIcon}
     <span class="icon-Placeholder-Padding">
-      <img src={fieldIcon} alt="Picker Icon" width="20" height="15" />
+      <img src={fieldIcon} alt="icon" width="20" height="15" />
     </span>
   {/if}
 
@@ -115,7 +115,7 @@
               <span class="icon-Padding">
                 <img
                   src={getOptionIcon(option, idx)}
-                  alt="test"
+                  alt="icon"
                   width="20"
                   height="15"
                 />