Log proposals and validations (#5291)

Adds detailed log messages for each validation and proposal received from the network.

include/xrpl/protocol/STValidation.h

@@ -30,6 +30,7 @@
 #include <functional>
 #include <memory>
 #include <optional>
+#include <sstream>
 
 namespace ripple {
 
@@ -141,6 +142,23 @@ public:
     Blob
     getSignature() const;
 
+    std::string
+    render() const
+    {
+        std::stringstream ss;
+        ss << "validation: "
+           << " ledger_hash: " << getLedgerHash()
+           << " consensus_hash: " << getConsensusHash()
+           << " sign_time: " << to_string(getSignTime())
+           << " seen_time: " << to_string(getSeenTime())
+           << " signer_public_key: " << getSignerPublic()
+           << " node_id: " << getNodeID() << " is_valid: " << isValid()
+           << " is_full: " << isFull() << " is_trusted: " << isTrusted()
+           << " signing_hash: " << getSigningHash()
+           << " base58: " << toBase58(TokenType::NodePublic, getSignerPublic());
+        return ss.str();
+    }
+
 private:
     static SOTemplate const&
     validationFormat();