Scan did not properly invoke the callback

[ivmarkov]

A small fix where the scan guard was missing this code:

let mut ot = self.activate();
let state = ot.state();

So scanning - in fact - did not work. :(

Two additional changes:

• CI fixed. The reason Clippy complains about "Two identical if blocks" (though they look different) is that they DO become identical (both empty) when neither defmt nor log is enabled
• Workspace. A small workspace ala "esp-mbedtls" was introduced so that fmt, clippy, quick rebuild etc. works from the root of the project.

[bjoernQ]

LGTM