0.46 provides post transaction handlers, could potentially migrate MsgFeeHandler to that

[arnabmitra]

Summary

0.46 provides post transaction handlers, could potentially migrate MsgFeeHandler to that.

Problem Definition

PostHandler are like AnteHandler (they share the same signature), but they execute after [RunMsgs](https://docs.cosmos.network/master/core/baseapp.html#runmsgs).

Like AnteHandlers, PostHandlers are theoretically optional, 

Also

Note, when PostHandlers fail, the state from runMsgs is also reverted, effectively making the transaction fail.

So fit's well, may require some finagling on current events being emitted but probably possible?

This would eliminate changes in our cosmos fork, make code easier to maintain etc.

Proposal

1.Add posthandler to provenance.

func NewPostHandler(options HandlerOptions) (sdk.AnteHandler, error) {
	// pseudo code
	postDecorators := []sdk.AnteDecorator{
		NewMsgFeeDecorator(options.MsgFeeKeeper),
	}

	return sdk.ChainAnteDecorators(postDecorators...), nil
}

2.Migrate MsgFeeHandler to be a postHandler

func (d msgFeeDecorator) AnteHandle(ctx sdk.Context, tx sdk.Tx, simulate bool, next sdk.AnteHandler) (sdk.Context, error)

3. verify wasm message's work and other tests pass.

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For Admin Use

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• Appropriate labels applied
• Appropriate contributors tagged
• Contributor assigned/self-assigned

[SpicyLemon]

They changed a bunch of stuff around with v0.46 and we need to fix it before we can ship v1.12. #1006 is for doing that.

They also replaced NewMempoolDecorator with NewDeductFeeDecorator. The NewDeductFeeDecorator function takes in a TxFeeChecker (func(ctx sdk.Context, tx sdk.Tx) (sdk.Coins, int64, error)) that might also be leveraged. So there's options.

[SpicyLemon]

I'm going to close this as a duplicate of #1006. There's some good stuff in here that will help with that one though.