Update local testnet scripts, fix eth1 sim (#1184)

* Update local testnet scripts

* Add logs when decrypting validators

* Update comment

* Update account manager

* Make random key generation explicit

* Remove unnecessary clap constraint

* Only decrypt voting keypair for eth1 deposit

* Use insecure kdf for insecure keypairs

* Simplify local testnet keygen

* Update local testnet

* Fix eth1 sim

* Add eth1 sim to CI again

* Remove old local testnet docs

* Tidy

* Remove checks for existing validators

* Tidy

* Fix typos

scripts/local_testnet/validator_client.sh

@@ -0,0 +1,18 @@
+#!/bin/bash
+
+#
+# Starts a validator client based upon a genesis state created by
+# `./local_testnet_genesis_state`.
+#
+
+source ./vars.env
+
+DEBUG_LEVEL=${1:-info}
+
+exec lighthouse \
+	--debug-level $DEBUG_LEVEL \
+	vc \
+	--datadir $VALIDATORS_DIR \
+	--secrets-dir $SECRETS_DIR \
+	--testnet-dir $TESTNET_DIR \
+	--auto-register