This changes the library the following way:

- The field class now also stores sizes and offsets in the message format
- The value class is overhauled to automatically cast to the right types based on the message definitions
- The value class can automatically cast to the users desired types
- The MessageFormat contains all information needed to parse the message
- The MessageFormats are resolved recursively once the header is received

allows derived classes to modify the data

…g place, with wrong length

…ptr to a field

…tible iterator

Co-authored-by: Beat Küng <[email protected]>