Third party billing services implementation

[DylanVerstraete]

Changed Events:

• nothing

New Events:

• in substrate-node/pallets/pallet-smart-contract/src/lib.rs

        /// A Service contract is created
        ServiceContractCreated(types::ServiceContract),
        /// A Service contract metadata is set
        ServiceContractMetadataSet(types::ServiceContract),
        /// A Service contract fees are set
        ServiceContractFeesSet(types::ServiceContract),
        /// A Service contract is approved
        ServiceContractApproved(types::ServiceContract),
        /// A Service contract is canceled
        ServiceContractCanceled {
            service_contract_id: u64,
            cause: types::Cause,
        },
        /// A Service contract is billed
        ServiceContractBilled {
            service_contract: types::ServiceContract,
            bill: types::ServiceContractBill,
            amount: BalanceOf<T>,
        },

[DylanVerstraete]

@renauter Please list the changed / new events above

[renauter]

@renauter Please list the changed / new events above

done
it should stay like this but I ll update if there are new changes

[DylanVerstraete]

time to complete: 1 day max