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

test/README.md

@@ -14,3 +14,9 @@ and run the following tests in docker containers:
     - counter app over grpc
 - persistence tests
     - crash tendermint at each of many predefined points, restart, and ensure it syncs properly with the app
+
+## Fuzzing
+
+[Fuzzing](https://en.wikipedia.org/wiki/Fuzzing) of various system inputs.
+
+See `./fuzz/README.md` for more details.