Assets-pallet chain-extension

[PierreOssun]

Pull Request Summary

This PR adds a 1 on 1 map of pallet-assets functions to chain-extension. For each extrinsic:

• charge the weight before entering the pallet call
• the origin signer is defined by an Origin enum that takes either Caller or Contract as value. This way the contract can chose between making call on behalf of the caller or on behalf of itself
• return a Retval (0 for success or an error number that will be decoded on contract side)

integrations tests here: https://github.com/AstarNetwork/chain-extension-contracts/pull/11

Check list

• [x] implemented chain-extension

[PierreOssun]

Closed this one Reopen on #132