Derive Macro xcm_procedural::Builder

#[derive(Builder)]
{
    // Attributes available to this derive:
    #[builder]
}

This is called on the Instruction enum, not on the Xcm struct, and allows for the following syntax for building XCMs: let message = Xcm::builder() .withdraw_asset(assets) .buy_execution(fees, weight_limit) .deposit_asset(assets, beneficiary) .build();