[Code refactoring]: move shared structures/functions to cortexbrain-common crate

[LorenzoTettamanti]

Is your feature request related to a problem?

• Yes

Problem Description:

Some user space structures (e.g. PacketLog) are initialized multiple times increasing the percentage of errors or potential bugs in the codebase.

Solution:

move the duplicated structures and functions to the cortexbrain-common crate under a dedicated feature flag. For example the structures needs to be organized using a #[cfg(feature="structs")] and the map handlers functions under a #[cfg(feature="map-handlers")]

Additional info

Check this files for duplicated structures or functions:
api.rs
map-handlers.rs
program-handlers.rs