Optionally don't send message on param constructions

[aarondr77]

The new useSyncedParams doesn't let us decide to not send the message on the first creation of the params. There are several places that we want to do this:

1. Deduplication -- we don't want to send the deduplicate message because the params default to no deduplication occuring. We don't want to add the deduplication step until the user actually takes an action
2. Concat -- If the user doesn't have any data in the sheet, we want to display the DefaultEmptyTaskpane, in which case we don't want to send a concat message.

I think a good approach to this is just to add an optional param to useSyncedParams called supressSendOnParamCreation. I know that we're trying to avoid adding a lot of params to the useSyncedParams, but I think the param is worth the functionality that we desire.