Wrap filter_panel_ui/srv into teal_transform_module

[gogonzo]

Filter-panel should have reactive teal_data as an input and ouput filtered data (as reactive teal_data).

teal_transform_module(
  ui = <filter panel ui>,
  server = <filter panel server> ,
  label = "Filters"
)

This isn't straightforward as filter_panel_server now doesn't return anything. We will need to create a new filter_panel_ui/srv function in teal and do so that it returns data.

[gogonzo]

Closing this one as it is not necessary. We gain nothing out of it.