Add multi option select and multi table view field select components

packages/builder/src/components/userInterface/MultiOptionSelect.svelte

@@ -0,0 +1,39 @@
+<script>
+  import { Multiselect } from "@budibase/bbui"
+
+  export let options = []
+  export let value = []
+  export let styleBindingProperty
+  export let onChange = () => {}
+
+  let boundValue = getValidOptions(value, options)
+  $: setValue(boundValue)
+  $: sanitiseOptions(options)
+
+  function getValidOptions(selectedOptions, allOptions) {
+    return selectedOptions.filter(val => allOptions.indexOf(val) !== -1)
+  }
+
+  function setValue(val) {
+    console.log(val)
+    onChange(val)
+  }
+
+  function sanitiseOptions(options) {
+    boundValue = getValidOptions(value, options)
+  }
+</script>
+
+<div>
+  <Multiselect extraThin secondary bind:value={boundValue}>
+    {#each options as option}
+      <option value={option}>{option}</option>
+    {/each}
+  </Multiselect>
+</div>
+
+<style>
+  div {
+    flex: 1 1 auto;
+  }
+</style>

packages/builder/src/components/userInterface/MultiTableViewFieldSelect.svelte

@@ -0,0 +1,5 @@
+<script>
+  import TableViewFieldSelect from "./TableViewFieldSelect.svelte"
+</script>
+
+<TableViewFieldSelect {...$$props} multiselect />

packages/builder/src/components/userInterface/TableViewFieldSelect.svelte

@@ -1,11 +1,12 @@
 <script>
   import OptionSelect from "./OptionSelect.svelte"
   import { backendUiStore } from "builderStore"
-  import { onMount } from "svelte"
+  import MultiOptionSelect from "./MultiOptionSelect.svelte"
 
   export let componentInstance = {}
   export let value = ""
-  export let onChange = (val = {})
+  export let onChange = () => {}
+  export let multiselect = false
 
   const tables = $backendUiStore.tables
 
@@ -24,4 +25,8 @@
   }
 </script>
 
-<OptionSelect {value} {onChange} {options} />
+{#if multiselect}
+  <MultiOptionSelect {value} {onChange} {options} />
+{:else}
+  <OptionSelect {value} {onChange} {options} />
+{/if}