Implement `From<model::*> for Value`

[MrFoxPro]

So instead of

let args = named_args! {
   "id" => edb_model::Uuid::from_str(&otp_request.id)?.to_value()?,
   "confirmed_at" => edb_model::Datetime::try_from(Utc::now())?.to_value()?
};

we will write

let args = named_args! {
   "id" => edb_model::Uuid::from_str(&otp_request.id)?,
   "confirmed_at" => edb_model::Datetime::try_from(Utc::now())?
};

Note: I'm using .expect() and not try_from because as I saw all to_value implementations do not fail at all