message: Add changelog entry for RuntimeError update
diff: ## **[Unreleased]**
  +- [#1401](https://github.com/wasmerio/wasmer/pull/1401) Make breaking change to `RuntimeError`: `RuntimeError` is now more explicit about its possible error values allowing for better insight into why a call may have failed.
  - [#1382](https://github.com/wasmerio/wasmer/pull/1382) Refactored test infranstructure (part 2)
  - [#1380](https://github.com/wasmerio/wasmer/pull/1380) Refactored test infranstructure (part 1)
  - [#1357](https://github.com/wasmerio/wasmer/pull/1357) Refactored bin commands into separate files
  