message: core: Add u8 to the list of generated Value implementations
  ## Motivation
  u8 had been forgotten from the list of automatically generated
  implementations for the Value Trait. See bug report
  ## Solution
  Added u8 to the list of automatically generated implementations for the
  Value Trait.
  Fixes:
diff: @@ -314,7 +314,7 @@ macro_rules! impl_value {
  impl_values! {
  record_u64(u64),
  - record_u64(usize, u32, u16 as u64),
  + record_u64(usize, u32, u16, u8 as u64),
  record_i64(i64),
  record_i64(isize, i32, i16, i8 as i64),
  record_bool(bool)
  