FEAT: http client may not need root cert

[Masber]

in mesa, all http clients need a root cert in order to interact with backend.
This is not the case with OCHAMI (at least on test environments)
refactor http clients to root cert to Option<&[u8]>

Tasks:
change all http clients so root_cert input is optional (make this change one by one by calling the function as Some(root_cert))
change settings struct to root_cert is optional field and change the http client functions call from Some(root_cert) to root_cert_opt