QBONE QUIC version retry: break on region redirect.

For legacy reasons, we try QUIC version RFCv1 many times before falling back to draft29.  This is to try to drive down the # of clients using draft29, which is supposed to be deprecated.

The current code, however, runs through all QUIC versions even when a redirect occurs, which is a bit silly because a successful redirect response actually indicates the QUIC version is good.

We should immediately fail the current connection attempt so that the host can be re-resolved to the redirected region.

Implementation changes:
- Added `REDIRECT` to `QboneTunnelInterface::State` enum.
- Updated `QboneTunnel::HandleIpRangeAssignment` to return `REDIRECT` when a region redirect response is received.
- Updated `QboneTunnel::WaitForEventsUntilState` to handle `REDIRECT` as a failure state.
- Updated `QboneTunnel::ConnectIfNeeded` to break out of the QUIC version loop if the connection failed due to `REDIRECT`.
- Added integration test `OutOfRegionClientHandlesRegionFqdnRedirectWithMultipleVersions` to verify that the version loop is broken on redirect and only one connection attempt is made to the original host.

PiperOrigin-RevId: 959194912

quiche/quic/qbone/bonnet/qbone_tunnel_interface.h

diff --git a/quiche/quic/qbone/bonnet/qbone_tunnel_interface.h b/quiche/quic/qbone/bonnet/qbone_tunnel_interface.h
index 6f67b79..07ffaa0 100644
--- a/quiche/quic/qbone/bonnet/qbone_tunnel_interface.h
+++ b/quiche/quic/qbone/bonnet/qbone_tunnel_interface.h
@@ -33,6 +33,7 @@
     END_REQUESTED,
     ENDED,
     FAILED,
+    REDIRECT,
   };
 
   // Wait and handle any events which occur.
@@ -75,6 +76,8 @@
         return "ENDED";
       case FAILED:
         return "FAILED";
+      case REDIRECT:
+        return "REDIRECT";
       default:
         return "UNKNOWN";
     }