LP1844812 Combobox avoids processing matching entry lists

LP1844812 Combobox avoids processing matching entry lists

Teach the combobox to only process newly provided entry lists if they
are different from the list already on record for the combobox.

The combobox entry list Input() is responsive to changes in data
throughout the life of the combobox.  As a new entry list is provided,
the component will perform various actions on the list.  However, in
many cases the list provided may be identical the list the component
already has, which can lead to a lot of unnecessary processing and in
some case an infinite loop of inputs and outputs.

Signed-off-by: Bill Erickson <berickxx@gmail.com>