test/fuzz: move fuzz tests into this repo (#5918)

Co-authored-by: Emmanuel T Odeke <emmanuel@orijtech.com>

Closes #5907

- add init-corpus to blockchain reactor
- remove validator-set FromBytes test
now that we have proto, we don't need to test it! bye amino
- simplify mempool test
do we want to test remote ABCI app?
- do not recreate mux on every crash in jsonrpc test
- update p2p pex reactor test
- remove p2p/listener test
the API has changed + I did not understand what it's tested anyway
- update secretconnection test
- add readme and makefile
- list inputs in readme
- add nightly workflow
- remove blockchain fuzz test
EncodeMsg / DecodeMsg no longer exist

go.mod

@@ -9,7 +9,7 @@ require (
 	github.com/btcsuite/btcd v0.21.0-beta
 	github.com/btcsuite/btcutil v1.0.2
 	github.com/confio/ics23/go v0.6.3
-	github.com/cosmos/iavl v0.15.0-rc5
+	github.com/cosmos/iavl v0.15.3
 	github.com/fortytw2/leaktest v1.3.0
 	github.com/go-kit/kit v0.10.0
 	github.com/go-logfmt/logfmt v0.5.0