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

.gitignore

@@ -40,4 +40,8 @@ test/e2e/networks/*/
 test/logs
 test/maverick/maverick
 test/p2p/data/
-vendor
+vendor
+test/fuzz/**/corpus
+test/fuzz/**/crashers
+test/fuzz/**/suppressions
+test/fuzz/**/*.zip