Moves QuicTag typedefs, and QuicTag utility methods to quic_tag.{h,cc}. No behavior change.

net/quic/core/crypto/quic_crypto_server_config.cc

Index: net/quic/core/crypto/quic_crypto_server_config.cc
diff --git a/net/quic/core/crypto/quic_crypto_server_config.cc b/net/quic/core/crypto/quic_crypto_server_config.cc
index a3093a5019b322b2900fe9a3cfbb8d66c5004738..46b3a6fb1247504b982b320b6cd5c12965d050f0 100644
--- a/net/quic/core/crypto/quic_crypto_server_config.cc
+++ b/net/quic/core/crypto/quic_crypto_server_config.cc
@@ -867,11 +867,11 @@ void QuicCryptoServerConfig::ProcessClientHelloAfterGetProof(
   }
 
   size_t key_exchange_index;
-  if (!QuicUtils::FindMutualTag(requested_config->aead, their_aeads,
-                                num_their_aeads, &params->aead, nullptr) ||
-      !QuicUtils::FindMutualTag(requested_config->kexs, their_key_exchanges,
-                                num_their_key_exchanges, &params->key_exchange,
-                                &key_exchange_index)) {
+  if (!FindMutualQuicTag(requested_config->aead, their_aeads, num_their_aeads,
+                         &params->aead, nullptr) ||
+      !FindMutualQuicTag(requested_config->kexs, their_key_exchanges,
+                         num_their_key_exchanges, &params->key_exchange,
+                         &key_exchange_index)) {
     helper.Fail(QUIC_CRYPTO_NO_SUPPORT, "Unsupported AEAD or KEXS");
     return;
   }
@@ -883,9 +883,9 @@ void QuicCryptoServerConfig::ProcessClientHelloAfterGetProof(
       case QUIC_CRYPTO_MESSAGE_PARAMETER_NOT_FOUND:
         break;
       case QUIC_NO_ERROR:
-        if (QuicUtils::FindMutualTag(
-                requested_config->tb_key_params, their_tbkps, num_their_tbkps,
-                &params->token_binding_key_param, nullptr)) {
+        if (FindMutualQuicTag(requested_config->tb_key_params, their_tbkps,
+                              num_their_tbkps, &params->token_binding_key_param,
+                              nullptr)) {
           break;
         }
       default: