feat(e2e): native token transfer from cosmos to starknet

[rnbguy]

Partially resolves #170 #171

ics20 transfer: cosmos -> starknet -> cosmos

• mint on starknet
• burn on starknet

[rnbguy]

Current test fails because of cosmos/ibc-rs#1262. The fix is present in ibc-go v9

Update: started using ibc-go v9 9929d13

[rnbguy]

Currently, the test fails, as the Starknet doesn't accept packet_ack because of commitment mismatch.

Update: I forgot to add the trace prefix. cd0f882

[Farhad-Shabani]

When a token is created, the ICS20 emits a CreateTokenEvent that includes the token's address. We can read the address by retrieving that event.

[rnbguy]

The comment is mainly about how to use relay_packet and still get the token address. The hack, that you pointed in #172 (comment), is introduced exactly for this.

[rnbguy]

I wanted to perform erc20 token transfer from starknet to cosmos, but I realized, we need to permit the ics20 contract on behalf of the sender. I am not sure how to do that.

I am making this PR final. Let's test starknet -> cosmos -> starknet on a different PR.

[Farhad-Shabani]

@rnbguy Now that the test is working, we can be confident in the correctness of our implementation on both the relayer and contracts side. My suggestion is to address #172 (comment) and #172 (comment) first, update the PR, and then wrap it up.

[Farhad-Shabani]

I wanted to perform erc20 token transfer from starknet to cosmos, but I realized, we need to permit the ics20 contract on behalf of the sender. I am not sure how to do that.

The way it works at the moment, users should approve their allowance before initiating a send_transfer like it's done here in the contract's unit tests.

[Farhad-Shabani]

By the way, I approve the PR, leaving that to you how to organize issues/PRs moving forward.