Fix a few Coverity warnings from the session manager work

- Be explicit about setting the copied flag in session::Key. Coverity seems
  confused about when that flag is set if it gets set by default
  initialization. This should fix 1452757 and 1452759.
- Explicitly copy the fields in ConnKey instead of using memcpy. Fixes
  1452758.

src/IPAddr.cc

@@ -44,12 +44,26 @@ ConnKey::ConnKey(const IPAddr& src, const IPAddr& dst, uint16_t src_port,
 		}
 	}
 
-detail::ConnKey::ConnKey(const ConnTuple& id)
+ConnKey::ConnKey(const ConnTuple& id)
 	: ConnKey(id.src_addr, id.dst_addr, id.src_port, id.dst_port,
 	          id.proto, id.is_one_way)
 	{
 	}
 
+ConnKey& ConnKey::operator=(const ConnKey& rhs)
+	{
+	if ( this == &rhs )
+		return *this;
+
+	memcpy(&ip1, &rhs.ip1, sizeof(in6_addr));
+	memcpy(&ip2, &rhs.ip2, sizeof(in6_addr));
+	port1 = rhs.port1;
+	port2 = rhs.port2;
+	transport = rhs.transport;
+
+	return *this;
+	}
+
 } // namespace detail
 
 IPAddr::IPAddr(const String& s)

src/IPAddr.h

@@ -4,7 +4,7 @@
 
 #include <netinet/in.h>
 #include <arpa/inet.h>
-#include <string.h>
+#include <cstring>
 #include <string>
 #include <memory>
 
@@ -43,13 +43,7 @@ struct ConnKey {
 	bool operator>=(const ConnKey& rhs) const { return memcmp(this, &rhs, sizeof(ConnKey)) >= 0; }
 	bool operator>(const ConnKey& rhs) const { return memcmp(this, &rhs, sizeof(ConnKey)) > 0; }
 
-	ConnKey& operator=(const ConnKey& rhs)
-		{
-		if ( this != &rhs )
-			memcpy(this, &rhs, sizeof(ConnKey));
-
-		return *this;
-		}
+	ConnKey& operator=(const ConnKey& rhs);
 };
 
 using ConnIDKey [[deprecated("Remove in v5.1. Use zeek::detail::ConnKey.")]] = ConnKey;

src/session/Key.cc

@@ -7,8 +7,11 @@ namespace zeek::session::detail {
 Key::Key(const void* session, size_t size, bool copy) : size(size)
 	{
 	data = reinterpret_cast<const uint8_t*>(session);
+
 	if ( copy )
 		CopyData();
+
+	copied = copy;
 	}
 
 Key::Key(Key&& rhs)