Qck 501 intents as memofield

[joe-bowman]

1. Summary

Fixes QCK-501

Legacy memoized intent with new memofields appended fails when validator address contains 0xFF

Change makes intents a memorized field.

2.Type of change

• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update
• This change requires that the relevant front end changes are deployed at the same time, as legacy memo format will no longer be supported.

3. Implementation details

Memoized intent becomes a length-prefixed memofield, with prefix 0x02, removing the need for a separator (as addresses can contain 0x00 through 0xff so no separator character would be valid).

7. Future Work (optional)

Front end must be updated to prefix the memoized intent with two bytes - [0x02, len(intent_bytes)]

[aljo242]

lgtm

This is a great simplification and improvement of what we already have !

[ajansari95]

lgtm🚢