Update: add snatch apart functions and improve logic of fss snatch functions

Update: add snatch apart functions and improve logic of fss snatch functions

The snatch apart is to create separate sets of strings instead of merging them.
The snatch mash apart will mash all dynamic strings for all content for a single object but use separate strings for each separate object.

I accidentally, or perhaps habitually, used break when return is better when handling errors.
Make sure to document f_string_max_size as a possible return result.