#90 handle native json field in datagrid

packages/web/src/celldata/TextCellView.svelte

@@ -1,6 +1,19 @@
 <script lang="ts">
+  import _ from 'lodash';
+
   export let selection;
   export let wrap;
 </script>
 
-<textarea class="flex1" {wrap} readonly value={selection.map(cell => cell.value).join('\n')} />
+<textarea
+  class="flex1"
+  {wrap}
+  readonly
+  value={selection
+    .map(cell => {
+      const { value } = cell;
+      if (_.isPlainObject(value) || _.isArray(value)) return JSON.stringify(value, undefined, 2);
+      return cell.value;
+    })
+    .join('\n')}
+/>