YT-23616: Support ProxyRole in TCreateClientOptions

commit_hash:9ae5443415404568faae52d025c9c0fcbd8b8db4

Author: hiddenpath

yt/cpp/mapreduce/client/client.cpp

@@ -1545,6 +1545,10 @@ TClientContext CreateClientContext(
         context.ServerName = Format("tvm.%v", context.ServerName);
     }
 
+    if (options.ProxyRole_) {
+        context.Config->Hosts = "hosts?role=" + *options.ProxyRole_;
+    }
+
     if (context.UseTLS || options.UseCoreHttpClient_) {
         context.HttpClient = NHttpClient::CreateCoreHttpClient(context.UseTLS, context.Config);
     } else {

yt/cpp/mapreduce/interface/client_method_options.h

@@ -1118,6 +1118,9 @@ struct TCreateClientOptions
 
     /// @brief Proxy Address to be used for connection
     FLUENT_FIELD_OPTION(TString, ProxyAddress);
+
+    /// @brief Desired proxy role to be used for connection.
+    FLUENT_FIELD_OPTION(TString, ProxyRole);
 };
 
 ///