YT-19324: move YT provider to ydb/library/yql

This commit is formed by the following script: https://paste.yandex-team.ru/6f92e4b8-efc5-4d34-948b-15ee2accd7e7/text.
This commit has zero effect on all projects that depend on YQL.

The summary of changes:
- `yql/providers/yt -> ydb/library/yql/providers/yt `- the whole implementation of YT provider is moved into YDB code base for further export as a part of YT YQL plugin shared library;
- `yql/providers/stat/{expr_nodes,uploader} -> ydb/library/yql/providers/stat/{expr_nodes,uploader}` - a small interface without implementation and the description of stat expr nodes;
- `yql/core/extract_predicate/ut -> ydb/library/yql/core/extract_predicate/ut`;
- `yql/core/{ut,ut_common} -> ydb/library/yql/core/{ut,ut_common}`;
- `yql/core` is gone;
- `yql/library/url_preprocessing -> ydb/library/yql/core/url_preprocessing`.

**NB**: all new targets inside `ydb/` are under `IF (NOT CMAKE_EXPORT)` clause which disables them from open-source cmake generation and ya make build. They will be enabled in the subsequent commits.

1 files changed, 63 insertions, 0 deletions

diff --git a/library/cpp/skiff/public.h b/library/cpp/skiff/public.h
new file mode 100644
index 00000000000..d67c6f26ee6
--- /dev/null
+++ b/library/cpp/skiff/public.h
@@ -0,0 +1,63 @@
+#pragma once
+
+#include <vector>
+#include <memory>
+
+namespace NSkiff {
+
+////////////////////////////////////////////////////////////////////////////////
+
+enum class EWireType
+{
+    Nothing  /* "nothing" */,
+    Int8     /* "int8" */,
+    Int16    /* "int16" */,
+    Int32    /* "int32" */,
+    Int64    /* "int64" */,
+    Int128   /* "int128" */,
+    Uint8    /* "uint8" */,
+    Uint16   /* "uint16" */,
+    Uint32   /* "uint32" */,
+    Uint64   /* "uint64" */,
+    Uint128  /* "uint128" */,
+    Double   /* "double" */,
+    Boolean  /* "boolean" */,
+    String32 /* "string32" */,
+    Yson32   /* "yson32" */,
+
+    Tuple             /* "tuple" */,
+    Variant8          /* "variant8" */,
+    Variant16         /* "variant16" */,
+    RepeatedVariant8  /* "repeated_variant8" */,
+    RepeatedVariant16 /* "repeated_variant16" */,
+};
+
+////////////////////////////////////////////////////////////////////////////////
+
+class TSkiffSchema;
+using TSkiffSchemaPtr = std::shared_ptr<TSkiffSchema>;
+
+using TSkiffSchemaList = std::vector<TSkiffSchemaPtr>;
+
+class TSimpleTypeSchema;
+using TSimpleTypeSchemaPtr = std::shared_ptr<TSimpleTypeSchema>;
+
+class TSkiffValidator;
+
+class TUncheckedSkiffParser;
+class TCheckedSkiffParser;
+
+class TUncheckedSkiffWriter;
+class TCheckedSkiffWriter;
+
+#ifdef DEBUG
+using TCheckedInDebugSkiffParser = TCheckedSkiffParser;
+using TCheckedInDebugSkiffWriter = TCheckedSkiffWriter;
+#else
+using TCheckedInDebugSkiffParser = TUncheckedSkiffParser;
+using TCheckedInDebugSkiffWriter = TUncheckedSkiffWriter;
+#endif
+
+////////////////////////////////////////////////////////////////////////////////
+
+} // namespace NSkiff