[BP: release/v4 <- #202] refactor: remove the ability to take a fee for each forwarded packet

[mergify]

Previously the PFM had a parameter that was used to take a percentage of each transfer that was forward through it, which would then be sent to the community pool. After many years of being used on many chains we found that absolutely no one was utilizing this feature and that it likely didn't make sense in the context of how PFM was actually used out in the wild. Rather than trying to maintain this feature we decided that we would just remove this functionality from the PFM all together.

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This is an automatic backport of pull request #202 done by Mergify.

[mergify]

Cherry-pick of 26d8080 has failed:

On branch mergify/bp/release/v4/pr-202
Your branch is up to date with 'origin/release/v4'.

You are currently cherry-picking commit 26d8080.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	modified:   middleware/packet-forward-middleware/packetforward/types/genesis.go
	modified:   middleware/packet-forward-middleware/packetforward/types/keys.go

Unmerged paths:
  (use "git add/rm <file>..." as appropriate to mark resolution)
	both modified:   middleware/packet-forward-middleware/Makefile
	both modified:   middleware/packet-forward-middleware/e2e/forward_timeout_test.go
	deleted by us:   middleware/packet-forward-middleware/e2e/upgrade_test.go
	both modified:   middleware/packet-forward-middleware/go.mod
	deleted by them: middleware/packet-forward-middleware/packetforward/client/cli/cli.go
	both modified:   middleware/packet-forward-middleware/packetforward/keeper/genesis.go
	deleted by them: middleware/packet-forward-middleware/packetforward/keeper/grpc_query.go
	both modified:   middleware/packet-forward-middleware/packetforward/keeper/keeper.go
	deleted by them: middleware/packet-forward-middleware/packetforward/keeper/params.go
	both modified:   middleware/packet-forward-middleware/packetforward/module.go
	both modified:   middleware/packet-forward-middleware/packetforward/module_test.go
	deleted by us:   middleware/packet-forward-middleware/packetforward/types/codec.go
	both modified:   middleware/packet-forward-middleware/packetforward/types/expected_keepers.go
	both modified:   middleware/packet-forward-middleware/packetforward/types/genesis.pb.go
	deleted by them: middleware/packet-forward-middleware/packetforward/types/params.go
	deleted by them: middleware/packet-forward-middleware/packetforward/types/query.pb.go
	deleted by them: middleware/packet-forward-middleware/packetforward/types/query.pb.gw.go
	both modified:   middleware/packet-forward-middleware/proto/packetforward/v1/genesis.proto
	deleted by them: middleware/packet-forward-middleware/proto/packetforward/v1/query.proto
	both modified:   middleware/packet-forward-middleware/test/mock/bank_keeper.go
	both modified:   middleware/packet-forward-middleware/test/mock/channel_keeper.go
	deleted by them: middleware/packet-forward-middleware/test/mock/distribution_keeper.go
	both modified:   middleware/packet-forward-middleware/test/mock/ibc_module.go
	both modified:   middleware/packet-forward-middleware/test/mock/ics4_wrapper.go
	both modified:   middleware/packet-forward-middleware/test/mock/transfer_keeper.go
	both modified:   middleware/packet-forward-middleware/test/setup.go
	deleted by us:   middleware/packet-forward-middleware/testing/simapp/app.go
	deleted by us:   middleware/packet-forward-middleware/testing/simapp/upgrades/upgrades.go

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

[jtieri]

Not backporting these changes to release/v5 or release/v4 since the associated ibc-go versions are officially EOL. If there is interest in these changes being backported we are happy to review PRs from external contributors or we can offer an upgrade service to get folks onto the latest and greatest versions of ibc-go, Cosmos SDK, and CometBFT. More information will be available soon.