`Tip` should implement `From`/`Into` `u64`

[tdelabro]

#[derive(
    Clone,
    Copy,
    Debug,
    Default,
    Deserialize,
    Eq,
    Hash,
    Ord,
    PartialEq,
    PartialOrd,
    Serialize,
    derive_more::Deref,
)]
#[cfg_attr(
    feature = "parity-scale-codec",
    derive(parity_scale_codec::Encode, parity_scale_codec::Decode)
)]
#[cfg_attr(feature = "scale-info", derive(scale_info::TypeInfo))]
#[serde(from = "PrefixedBytesAsHex<8_usize>", into = "PrefixedBytesAsHex<8_usize>")]
pub struct Tip(pub u64);

As mention in #197 don't use deref. Use From/Into instead