Move callbacks middleware down the middleware stack

[srdtrk]

Summary

Wire up the Callbacks Middleware so that it is the middle app in the middleware stack.

Problem Definition

See this thread for a detailed explanation. The main issue with the current setup is that it wouldn't have worked if callbacks had a version.

• Change the wiring of the transfer stack in callbacks/simapp
• Change the wiring of the icacontroller stack in callbacks/simapp
• Update the callbacks middleware documentation integration.md

Proposal

For example, the ICA controller stack would look like:

    var icaControllerStack porttypes.IBCModule
    icaControllerStack = icacontroller.NewIBCMiddleware(nil, app.ICAControllerKeeper)
    icaControllerStack = ibccallbacks.NewIBCMiddleware(icaControllerStack, app.IBCFeeKeeper, app.MockContractKeeper, maxCallbackGas)
    // Since the callbacks middleware itself is an ics4wrapper, it needs to be passed to the ica controller keeper
    app.ICAControllerKeeper.WithICS4Wrapper(icaControllerStack.(porttypes.Middleware))
    
    icaControllerStack = ibcfee.NewIBCMiddleware(icaControllerStack, app.IBCFeeKeeper)

---

For Admin Use

• Not duplicate issue
• Appropriate labels applied
• Appropriate contributors tagged/assigned

[srdtrk]

Rewiring transfer stack this way causes some unit tests in ibc_middleware_test.go to fail. Since the middleware is initialised in the middle of the stack. There would be no way to unit test its SendPacket without also testing other functions. I think we should address this after #4329 and #4328