Cancel-xxx, input validation, ecosystem checks

- trade_MP can be used with zero amounts
- trade_MP can be used with non existing properties
- fixes behavior where raw encoded offer with zero units for sale fails, but zero units desired passes etc.
- guards and fillins of todos for "meta dex logic math"

... and cancel-everything that behaves as follows:

- both properties in main ecosystem -> cancel main properties
- both properties in test ecosystem -> cancel test properties
- cross ecosystem values (...) cancel offers of both ecosystems

Consider the last part as debatable of course.