Add clarity to errors with incorrect fields.

[SomeRanDev]

[ERROR] src/systems/AccountSync.hx:97: characters 16-34

 97 |     var size = orders[aid].size();
    |                ^^^^^^^^^^^^^^^^^^
    | `MagicArrayTools` function was used without calling `magiter` first. Please call `magiter` before running any other functions.

To help reduce user confusion, convert this error message to something that provides the underlying type:

Array<Int> has no field size.

If you're trying to use `MagicArrayTools.size`, you must first call `magiter`.