`Weight` function implementations unnecessarily verbose

Several of the Weight implementations are (as the title states) unnecessarily verbose:

• checked_* functions could be made much more succinct by using the ? operator not possible, see https://github.com/rust-lang/rust/issues/74935

• the any_*/all_* functions all follow the same pattern:

  复制

  // all_*
  self.ref_time OP other.ref_time && self.proof_size OP other.proof_size
  
  // any_*
  self.ref_time OP other.ref_time || self.proof_size OP other.proof_size

  which could very easily be implemented with a macro_rules!, and would reduce maintenance burden of any fields added in the future.

• the scalar arithmetic ops have their implementation duplicated, for example mul here:

  • https://github.com/paritytech/substrate/blob/master/primitives/weights/src/weight_v2.rs#L274-L276
  • https://github.com/paritytech/substrate/blob/master/primitives/weights/src/weight_v2.rs#L365-L373

  unfortunately not possible due to the current trait bounds on <Weight as Mul<T>>::mul

Also, Weight doesn't impl CheckedMul, which I think it should. not possible either

As always, happy to pick this up if it's accepted :slightly_smiling_face: