Add Stream.Mut.Fold.Foreign

[adithyaov]

• There is a lot of common code
• Can use CPP and extract out commonality
• This module is required as mutable arrays are important first-class citizens
• The only problem is the common code
• The logic is exactly the same and hence the only required review is how or whether to add this module

[harendra-kumar]

Can you please fix the docspec CI?