feat(rust): port lazy block matching

Move greedy, lazy, lazy2, and binary-tree block matchers into Rust. A narrow
C state projection preserves configuration-specific context layout while Rust
owns hash-chain, row-based, attached-dictionary, and external-dictionary
searches and sequence-store updates.

The component map now records the lazy family as migrated; the optimized
matcher and high-level contexts remain outside this commit.

Test Plan:
- cargo test --all-targets
- cargo test --target i686-unknown-linux-gnu --all-targets
- cargo clippy && cargo clippy --benches && cargo clippy --tests
- cargo +nightly fmt
- make -B -C tests -j2 fuzzer zstreamtest invalidDictionaries poolTests
- ./tests/fuzzer -s5346 -i1 --no-big-tests
- ./tests/zstreamtest -i3000 -s334462
- ./tests/invalidDictionaries
- timeout 20s stdbuf -oL ./tests/poolTests

Refs: rust/README.md

rust/README.md

@@ -33,16 +33,18 @@ zstd ABI:
     while preserving the compressor's Huffman-table repeat state.
   - `zstd_fast` and `zstd_double_fast` implement the single- and two-table
     fast block match finders, including attached and external dictionary paths.
+  - `zstd_lazy` implements greedy, lazy, lazy2, and binary-tree matching,
+    including row-based and dictionary search variants.
 - Runtime support
   - `threading` provides platform pthread wrappers required by zstd headers.
   - `pool` implements the bounded worker pool used by multithreaded compression.
 - Dictionary support
   - `zstd_ddict` owns, loads, copies, and references decode dictionaries.
 
-The lazy and optimal block matchers, general decompression, dictionary-building,
-legacy, and CLI translation units are still C. They must move before the
-rewrite is complete. Keeping that boundary explicit prevents a passing hybrid
-build from being mistaken for the final all-Rust result.
+The optimal block matcher, general decompression, dictionary-building, legacy,
+and CLI translation units are still C. They must move before the rewrite is
+complete. Keeping that boundary explicit prevents a passing hybrid build from
+being mistaken for the final all-Rust result.
 
 ## Compatibility boundary