[Task] Display reqwest errors source

[taorepoara]

What should be done

Reqwest almost display a same type that is not really explicit: error sending request for url ...

Display the source of the error too when it's present to have more information.

Technical recommendation

See this comment: https://users.rust-lang.org/t/source-in-thiserror-default-display/114573/2

Is this task linked with any other ?

#321
#322

_{Huly®: DOFIG-317}