[Snowbridge] Support Transact over the bridge

[acatangiu]

Description

Allow user agents on Polkadot to call Ethereum smart contracts on Ethereum from Polkadot chains using XCMs over Snowbridge. The "origin/caller" as seen by Ethereum callee is the Snowbridge agent contract controlled and owned by the original origin/caller chain on Polkadot.

Allow user agents on Ethereum to Transact on Polkadot chains by using XCMs over Snowbridge. The origin as seen by the Polkadot chain called function is the Ethereum XCM location of the original caller on Ethereum.

Progress

• RFC: Asset transfers can alias XCM origin on destination to original origin RFCs#122
• Implement in XCMv5 [xcm-v5] implement RFC#122: InitiateTransfer can alias XCM original origin on destination paritytech/polkadot-sdk#5971
• Integrate XCMv5 to Polkadot-SDK: XCM v5 paritytech/polkadot-sdk#4826
• XCM: Remove require_weight_at_most from Transact paritytech/polkadot-sdk#4284
• Snowbridge transact support: TODO: link issues
• Released in Polkadot-SDK: stableXXXX
• Integrated to Polkadot and Kusama system chains runtimes
• live on Polkadot and Kusama chains