feat(fs): introduce file system abstractions

[zjw1111]

Purpose

Linked issue: None

Migrate the basic file system abstractions from the Alibaba-origin C++ repository into Apache Paimon C++.

Requested files migrated:

• include/paimon/fs/file_system.h
• include/paimon/fs/file_system_factory.h
• src/paimon/common/fs/file_system.cpp
• src/paimon/common/fs/file_system_factory.cpp
• src/paimon/common/fs/resolving_file_system.h
• src/paimon/common/fs/resolving_file_system.cpp

Extra dependency files migrated for a complete build closure:

• include/paimon/factories/factory.h
• include/paimon/factories/factory_creator.h
• src/paimon/common/factories/factory_creator.cpp
• include/paimon/factories/singleton.h
• src/paimon/common/factories/singleton.cpp
• src/paimon/common/factories/io_hook.h
• src/paimon/common/factories/io_hook.cpp

License handling:

• Replaced Alibaba-owned file headers with ASF headers.
• Preserved the Alibaba Havenask-derived headers in singleton.h and singleton.cpp.
• Added the corresponding Havenask declaration to top-level LICENSE and NOTICE.

External contributor handling:

• Final blame analysis found no contributor above the automatic or file-level threshold.
• No Co-authored-by trailer was added.

Tests

• git diff --check
• clang-format on migrated C++ files
• Migration preflight: no missing internal dependencies
• External contributor analysis on the final migrated file list

Note: cmake --build build -j64 could not run in this checkout because the existing build/ directory has no generated Makefile or other usable build generator files.

API and Format

This adds public file system and factory headers under include/paimon/. It does not change storage format or protocol.

Documentation

No user-facing documentation changes.

Generative AI tooling

Migrate-by: OpenAI Codex

[leaves12138]

Thanks for migrating the file system abstractions. I found a blocking build/link issue in the current head.

Several newly added utility APIs are only declared, but no implementation is added in this PR. For example:

• Path::ToString, PathUtil::CreateTempPath, and PathUtil::ToPath are declared in src/paimon/common/utils/path_util.h, and are called by the new file system code.
• StringUtils::StartsWith, StringUtils::EndsWith, and StringUtils::ToLowerCase are declared in src/paimon/common/utils/string_utils.h, and existing/new code calls them from data_type_json_parser.cpp, blob_utils.cpp, and file_system.cpp.

I could not find any corresponding definitions in the PR. This means the code either fails to link as soon as those call sites are included in a target, or fails to build if these utilities are expected to be header-only. Please add the missing definitions (or inline the functions in the headers) and include tests/at least a build target that exercises the new file system and utility code.

I also noticed that this PR does not add any tests for the new path parsing / resolving file system behavior, so the cache key, default scheme mapping, and helper functions are currently unverified.