Figure out how to use magic numbers and fp

[danielmansson]

In the beginning, the plan was to use decimal for magic number constants. It looks quite clean and should be deterministic as long as there is no calculations happening.

fp value = 7.21m;
or
fp result = 13.2m * value;

For this implicit cast from decimal to fp is used. Looks pretty clean. Not a huge risk for mistake since decimal is rare to use in games. Performance is not great and it will probably generate garbage.

This will not work with Burst.

Explicit casts has the same problem.

Figure something out! :)