Additional e2e tests

[minghinmatthewlam]

Context and scope
We want to cover the various functional e2e use cases through tests.

Discussion and alternatives

• Basic send/receive between all variations of the four contracts
  • ERC20 source -> ERC20 destination
  • ERC20 source -> native destination
    • Additional NativeTokenDestination E2E tests #73
  • native source -> ERC20 destination
  • native source -> native destination
• Multihops between all variations of the contracts (doesn't need to be separate e2e test for each)
  • ERC20 source -> ERC20 destinations
  • ERC20 source -> native destinations
    • Additional NativeTokenDestination E2E tests #73
  • native source -> ERC20 destinations
  • native source -> native destinations
    • Additional NativeTokenDestination E2E tests #73
• Multihop between destination bridge address on the same chain
• The second send token for redirecting transfer fails, can we retry with Teleporter to deliver
• Taking a destination token bridge token and forming another bridging group by passing it as source?
• Chain gets compromised and tries to unwrap more than its balance.
• Sending funds to wrong a destination bridge that has no contract code yet, but will be deployed to later on #80

[michaelkaplan13]

My bad, didn't mean to close the issue. The comment in #73 had "partially fixes" this issue, and the "fixes" keyword caused Github to close it when the PR was merged.