Backing and Issuing renaming

[hackfisher]

Outdated:

• frame/bridge/ethereum/backing darwinia-ethereum-backing -> darwinia-substrate2ethereum-backing
• frame/bridge/ethereum/issuing darwinia-ethereum-issuing -> darwinia-ethereum2substrate-issuing
• frame/bridge/tron/backing/Cargo.toml darwinia-tron-backing -> darwinia-substrate2tron-backing

frame/bridge/crab/backing will later be replaced by substrate2substrate-backing.
frame/bridge/crab/issuing will later be replaced by substrate2substrate-issuing.

Pallet name in runtime should use this format too, such as Darwinia2EthereumBacking, Ethereum2DarwiniaIssuing Darwinia2CrabBacking etc.

[hackfisher]

From the perspective of mapping token protocol, there are two chains backing chain and issuing chain, backing chain is where mapping token's origin native token located, and issuing chain is where the mapping token located.

These backing and issuing pallet are for the uses of token layer and wormhole app, thus should be split from bridge folder, and move to a new wormhole folder.

Following is the suggested & simplified folder structure and naming:

• wormhole
  • backing
    • to-ethereum-backing
    • to-substrate-backing
    • to-tron-backing
  • issuing
    • from-ethereum-issuing
    • from-substrate-issuing
    • from-bsc-issuing

[aurexav]

* frame/bridge/ethereum/backing  darwinia-ethereum-backing -> darwinia-substrate2ethereum-backing

* frame/bridge/ethereum/issuing  darwinia-ethereum-issuing -> darwinia-ethereum2substrate-issuing

* frame/bridge/tron/backing/Cargo.toml darwinia-tron-backing -> darwinia-substrate2tron-backing

frame/bridge/crab/backing will later be replaced by substrate2substrate-backing.
frame/bridge/crab/issuing will later be replaced by substrate2substrate-issuing.

Pallet name in runtime should use this format too, such as Darwinia2EthereumBacking, Ethereum2DarwiniaIssuing Darwinia2CrabBacking etc.

According to the desc.

Darwinia2CrabBacking: substrate2substrate_backing::{Pallet, Storage, Config<T>} = 34,

This looks weird.

Should we make the substrate-backing pallet supporting multi-instances?

[hackfisher]

Should we make the substrate-backing pallet supporting multi-instances?

Maybe not now, just do restructure and rename this time.

[hackfisher]

This looks weird.

This quote is outdated, please use the latest comment:

Following is the suggested & simplified folder structure and naming:

• wormhole
  • backing
    • to-ethereum-backing
    • to-substrate-backing
    • to-tron-backing
  • issuing
    • from-ethereum-issuing
    • from-substrate-issuing
    • from-bsc-issuing