Issue 25140: Copy Quote to new customer/prospect

-- Needs to be considered along with the xtuple PR for the database changes

-- pull into 4.9
`_mode` and `_captive` don't seem to be used, although `_captive` does get set. Either use them or remove them. Also, weigh the merits of replacing a set of `private` fields with a single `copyQuotePrivate *_private` member (we need to discuss as a group what the variable name should be), where the `copyQuotePrivate` class is declared and defined entirely in `copyQuote.cpp`.