Fix sized messages (Follow-up on #2064) (#2103)

* Use wasm execution on millau and rialto

It's safer like this since here are some errors that aren't caught when
using native execution

* Revert "Revert "Fix max-size messages at test chains (#2064)" (#2077)"

This reverts commit 62f749e124fbcf074cdc9840690bb9049d4b3b99.

* Adjustments