Visible widget doesn't update with new 'groupby field' values

[droumis]

Code

```python from holonote.annotate import Annotator from holonote.app.tabulator import AnnotatorTable from holonote.app import PanelWidgets import panel as pn; pn.extension('tabulator') import holoviews as hv; hv.extension('bokeh') from holonote.annotate.connector import SQLiteDB annotator = Annotator({"height": float, "width": float}, fields=["type"], connector=SQLiteDB(filename=':memory:')) annotator.groupby = "type" annotator_widgets = pn.Column(PanelWidgets(annotator), AnnotatorTable(annotator)) pn.Column(annotator_widgets, annotator * hv.Image([], ['width', 'height'])).servable() ```

https://github.com/holoviz/holonote/assets/6613202/97513cb7-f039-4651-9e05-b5ab81bc02e5