[Turbopack] add persisting to the new backend (#69668)

### What?

Takes regular snapshots of the state of the system.

Stores task cache and task data in a lmdb database. 

Currently active operations are paused, stored and continued on restore.

Task Cache need large keys, so key hashing and lookup is added on top of
LMDB for that.

turbopack/crates/turbo-tasks-backend/Cargo.toml

@@ -12,21 +12,31 @@ bench = false
 [lints]
 workspace = true
 
+[features]
+default = []
+verify_serialization = []
+
 [dependencies]
 anyhow = { workspace = true }
 async-trait = { workspace = true }
 auto-hash-map = { workspace = true }
+byteorder = "1.5.0"
 dashmap = { workspace = true, features = ["raw-api"]}
 either = { workspace = true }
 hashbrown = { workspace = true }
 indexmap = { workspace = true }
+lmdb-rkv = "0.14.0"
 once_cell = { workspace = true }
 parking_lot = { workspace = true }
+pot = "3.0.0"
 rand = { workspace = true }
+rayon = { workspace = true }
 rustc-hash = { workspace = true }
 serde = { workspace = true }
+serde_path_to_error = { workspace = true }
 smallvec = { workspace = true }
 tokio = { workspace = true }
+tokio-scoped = "0.2.0"
 tracing = { workspace = true }
 turbo-prehash = { workspace = true }
 turbo-tasks = { workspace = true }