[feat] add transactional capabilities to kv_typed & add lmdb backend

rust-libs/tools/kv_typed/Cargo.toml

rust-libs/tools/kv_typed/benches/compare_backends.rs

rust-libs/tools/kv_typed/src/as_bytes.rs

rust-libs/tools/kv_typed/src/backend.rs

rust-libs/tools/kv_typed/src/backend/leveldb.rs

rust-libs/tools/kv_typed/src/backend/lmdb.rs

rust-libs/tools/kv_typed/src/backend/memory.rs

rust-libs/tools/kv_typed/src/backend/mock.rs

rust-libs/tools/kv_typed/src/backend/sled.rs

rust-libs/tools/kv_typed/src/backend/sled/transactional.rs

rust-libs/tools/kv_typed/src/batch.rs

rust-libs/tools/kv_typed/src/bytes.rs

rust-libs/tools/kv_typed/src/collection_inner.rs

rust-libs/tools/kv_typed/src/collection_ro.rs

rust-libs/tools/kv_typed/src/collection_rw.rs

rust-libs/tools/kv_typed/src/error.rs

rust-libs/tools/kv_typed/src/event.rs

rust-libs/tools/kv_typed/src/explorer.rs

rust-libs/tools/kv_typed/src/from_bytes.rs

rust-libs/tools/kv_typed/src/iter.rs