Improvements to prepare_delivery.sh

I think the stripping functionality of the script prepare_delivery.sh may be updated. Currently this line does not quite match the text in options.h and at least for me the command did not add anything to the list to be stripped.

https://forge.3gpp.org/rep/ivas-codec-pc/ivas-codec/-/blob/main/scripts/prepare_delivery.sh#L344

It may anyhow need a review for the next delivery, since I suppose also NONBE-switches should be removed. I would also like to add an option for excluding the zip-file preparation, if you only want to strip the code for comparing with the delivery code.