[apps/external] Move external API into Ion

[Yaya-Cout]

Is your feature request related to a problem? Please describe.
Ion contains all that is platform specific code. External API change with platform, so I crash when used in some cases.

Describe the solution you'd like
The External API (or at least the archive), should be moved in Ion, because it has not a lot of sense to keep it in apps, and it would be easier to manage if it's moved in Ion, so we can use it more easily. For example, we could use Ion to use the file system in the shared simulator part.

Additional context
See #289 for more context.