Use more strong types

[PatrickKa]

Description

Strong types make interfaces safer and more readable (see Strong types for strong interfaces). With the NamedType library, we can finally define and use them more easily. Therefore, we should refactor our current code and use more strong types.

To do

• Add and use a strong type for program ID #272
• Add strong types for fram::Address and fram::Size #308
• Use strong_type instead of NamedType for ProgramId #309
• Add a strong type for timestamps?
• ...