Add support for .lz and .lz4 compression algorithms

[yh-sb]

Added read-only support for lzip (.lz) and LZ4 (.lz4) compressed archives.

Here are files examples: archive.tar.lz, archive.tar.lz4

$ 7zz l ./archive.tar.lz

7-Zip (z) 25.01 (arm64) : Copyright (c) 1999-2025 Igor Pavlov : 2025-08-03
 64-bit arm_v:8-A locale=en_US.UTF-8 Threads:14 OPEN_MAX:1048575

Scanning the drive for archives:
1 file, 575105 bytes (562 KiB)

Listing archive: ./archive.tar.lz

--
Path = ./archive.tar.lz
Type = lzip

   Date      Time    Attr         Size   Compressed  Name
------------------- ----- ------------ ------------  ------------------------
                    .....                            archive.tar
------------------- ----- ------------ ------------  ------------------------
                                             575105  1 files

$ 7zz l ./archive.tar.lz4

7-Zip (z) 25.01 (arm64) : Copyright (c) 1999-2025 Igor Pavlov : 2025-08-03
 64-bit arm_v:8-A locale=en_US.UTF-8 Threads:14 OPEN_MAX:1048575

Scanning the drive for archives:
1 file, 580099 bytes (567 KiB)

Listing archive: ./archive.tar.lz4

--
Path = ./archive.tar.lz4
Type = lz4

   Date      Time    Attr         Size   Compressed  Name
------------------- ----- ------------ ------------  ------------------------
                    .....                            archive.tar
------------------- ----- ------------ ------------  ------------------------
                                             580099  1 files

[yh-sb]

Hi @ip7z,
Would you mind taking a look at this?

[gyurix]

Usefulness is high. Implementation is not ready yet.

LZ4 handler currently ignores header/block/content checksums and does not reject BlockIndependence == 0, even though dependent blocks need previous-block history. That can silently produce wrong output on valid frames.

Lzip handler is similarly partial: trailer CRC/member-size are not validated and concatenated members are ignored, so advertised .lz support is broader than actual implementation.

Merge readiness: 2/10. Before merge: validate required frame/trailer fields, reject unsupported features explicitly, and add corpus/tests for dependent blocks, concatenated members, and malformed inputs.