chore: remove OnChanUpgradeRestore callbacks and discard state changes on app upgrade callbacks (backport #5696)

[mergify]

This is an automatic backport of pull request #5696 done by Mergify.
Cherry-pick of 9faaff5 has failed:

On branch mergify/bp/release/v8.1.x/pr-5696
Your branch is up to date with 'origin/release/v8.1.x'.

You are currently cherry-picking commit 9faaff5f.
  (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:   modules/apps/27-interchain-accounts/controller/ibc_middleware.go
	modified:   modules/apps/27-interchain-accounts/controller/ibc_middleware_test.go
	modified:   modules/apps/27-interchain-accounts/host/ibc_module.go
	modified:   modules/apps/29-fee/ibc_middleware.go
	modified:   modules/apps/callbacks/ibc_middleware.go
	modified:   modules/apps/transfer/ibc_module.go
	modified:   modules/core/05-port/types/module.go
	modified:   testing/mock/events.go
	modified:   testing/mock/ibc_app.go
	modified:   testing/mock/ibc_module.go
	modified:   testing/mock/mock.go

Unmerged paths:
  (use "git add/rm <file>..." as appropriate to mark resolution)
	deleted by us:   docs/docs/01-ibc/06-channel-upgrades.md
	both modified:   modules/core/keeper/msg_server.go
	both modified:   modules/core/keeper/msg_server_test.go

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

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[damiannolan]

waiting on #5699