Redesign `callablePointSDKEventAttributes` function

[da1suk8]

This function came from #26.

It's a bit weird that the callstack comes first, so move it to the tail.

wasmd/x/wasmplus/keeper/events.go

Lines 42 to 50 in d6ea9ec

	func callablePointSDKEventAttributes(customAttributes []wasmvmtypes.EventAttribute, contractAddr sdk.AccAddress, callstack []byte) ([]sdk.Attribute, error) {
	attrs, err := wasmkeeper.ContractSDKEventAttributes(customAttributes, contractAddr)
	if err != nil {
	return nil, err
	}
	// attrs[0] is addr
	attrs = append([]sdk.Attribute{attrs[0], sdk.NewAttribute(wasmplustypes.AttributeKeyCallstack, string(callstack))}, attrs[1:]...)
	return attrs, nil
	}