ICS20-2: Add Token Forwarding ability to ICS20-2 (#1090)

* add recv logic and revert logic on error ack/timeout

* multiple denoms but still support forwarding

* lint

* Apply suggestions from code review

Co-authored-by: Carlos Rodriguez <[email protected]>

* address reviews

* Apply suggestions from code review

Co-authored-by: Carlos Rodriguez <[email protected]>

* small fixes

* generate forwarding address if it doesn't exist

* blank memo for now

* only do revertInFlightChanges or refund packets on error ack, not both

* make same changes for timeout

* forwarding info struct, individual memos

* fail early since forwarding must be atomic

* address some small review comments

* only set memo on last hop

* address Stefano's and my review comments

* missing bracket

* destinationChannel -> destChannel

* ICS20v2 path forwarding: simplify revert in-flight changes (#1110)

* simplify revert in-flight changes

* typo

* nit: rename ForwardingInfo to Forwarding (#1112)

* ICS20v2: use protobuf encoding for packet data of v2 (#1118)

* ics20: use protobuf encoding for packet data of v2

* Update README.md

* delete previously forwarded packet (#1119)

* Update spec/app/ics-020-fungible-token-transfer/README.md

Co-authored-by: Damian Nolan <[email protected]>

* Apply suggestions from code review

Co-authored-by: Cian Hatton <[email protected]>
Co-authored-by: Carlos Rodriguez <[email protected]>

* ICS20v2: use `Denom` and `Trace` types (#1115)

* nit: rename ForwardingInfo to Forwarding

* use Denom and Trace types

* Apply suggestions from code review

Co-authored-by: Aditya <[email protected]>

* comments

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Co-authored-by: Aditya <[email protected]>

* review comment

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Co-authored-by: Carlos Rodriguez <[email protected]>
Co-authored-by: Damian Nolan <[email protected]>
Co-authored-by: Cian Hatton <[email protected]>