LP1811288 Combobox support entrylist+async / id labels
Allow the caller to pass a seed entrylist value for async comboboxes.
This is useful when a value should be applied to the box on load instead
of waiting for user input for typeahead loading.
Allow combobox entries to default to using the 'id' field for the label
if no label is provided.
Signed-off-by: Bill Erickson <berickxx@gmail.com> Signed-off-by: Jane Sandberg <sandbej@linnbenton.edu> Signed-off-by: Dan Wells <dbw2@calvin.edu>