treewide: fix "Unhandled token" errors with Lua CBI maps

The `data-type` attribute is used to bind datatype validators to a widget
while some templates used the same attribute to denote the name of the
underlying widget.

Change the `data-type` attributes referring to the widget name to
`data-widget` in order to stop the JS token error spam.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>