Primary caching 2: Introduce FlatVecDeque (#4593)

Introduce `FlatVecDeque` (feel free to rename), the core datastructure
behind the primary cache.

You can view it as a "native", circular `ListArray`: it's a flattened
array of arrays, implemented as two ringbuffers, that stores actual
components (i.e. deserialized data) in a cache friendly way.
Also plenty of APIs to get data in and out, in and out of order.

Once again, these benchmarks are disabled on CI.

Some numbers for posterity / git log (5950X, Arch):
```
flat_vec_deque/insert/empty                     1.00    310.9±3.87ns  3.0 GElem/sec
flat_vec_deque/insert/prefilled/back            1.00     28.6±0.20µs 33.4 MElem/sec
flat_vec_deque/insert/prefilled/front           1.00     29.1±0.17µs 32.7 MElem/sec
flat_vec_deque/insert/prefilled/middle          1.00     42.8±0.57µs 22.3 MElem/sec
flat_vec_deque/insert_range/empty               1.00      3.5±0.04µs 1348.1 MElem/sec
flat_vec_deque/insert_range/prefilled/back      1.00     31.9±0.20µs 149.4 MElem/sec
flat_vec_deque/insert_range/prefilled/front     1.00     30.6±0.17µs 155.7 MElem/sec
flat_vec_deque/insert_range/prefilled/middle    1.00     46.3±0.20µs 102.9 MElem/sec
flat_vec_deque/insert_with/empty                1.00  1375.4±43.80ns  3.4 GElem/sec
flat_vec_deque/insert_with/prefilled/back       1.00     30.1±0.16µs 158.6 MElem/sec
flat_vec_deque/insert_with/prefilled/front      1.00     27.8±0.83µs 171.5 MElem/sec
flat_vec_deque/insert_with/prefilled/middle     1.00     44.8±0.34µs 106.4 MElem/sec
flat_vec_deque/range/prefilled/back             1.00     15.3±0.05µs 312.3 MElem/sec
flat_vec_deque/range/prefilled/front            1.00     15.8±0.15µs 301.2 MElem/sec
flat_vec_deque/range/prefilled/middle           1.00     14.8±0.09µs 323.2 MElem/sec
flat_vec_deque/remove/prefilled/back            1.00     14.4±0.07µs 67.8 KElem/sec
flat_vec_deque/remove/prefilled/front           1.00     28.5±0.28µs 34.2 KElem/sec
flat_vec_deque/remove/prefilled/middle          1.00     28.5±0.11µs 34.3 KElem/sec
flat_vec_deque/remove_range/prefilled/back      1.00     14.6±0.07µs 326.0 MElem/sec
flat_vec_deque/remove_range/prefilled/front     1.00     28.6±0.16µs 166.7 MElem/sec
flat_vec_deque/remove_range/prefilled/middle    1.00     29.3±0.17µs 162.8 MElem/sec
```

---

Part of the primary caching series of PR (index search, joins,
deserialization):
- #4592
- #4593

Cargo.toml

@@ -45,6 +45,7 @@ re_log_encoding = { path = "crates/re_log_encoding", version = "=0.12.0-alpha.3"
 re_log_types = { path = "crates/re_log_types", version = "=0.12.0-alpha.3", default-features = false }
 re_memory = { path = "crates/re_memory", version = "=0.12.0-alpha.3", default-features = false }
 re_query = { path = "crates/re_query", version = "=0.12.0-alpha.3", default-features = false }
+re_query_cache = { path = "crates/re_query_cache", version = "=0.12.0-alpha.3", default-features = false }
 re_renderer = { path = "crates/re_renderer", version = "=0.12.0-alpha.3", default-features = false }
 re_sdk = { path = "crates/re_sdk", version = "=0.12.0-alpha.3", default-features = false }
 re_sdk_comms = { path = "crates/re_sdk_comms", version = "=0.12.0-alpha.3", default-features = false }

crates/re_query_cache/Cargo.toml

@@ -0,0 +1,49 @@
+[package]
+name = "re_query_cache"
+authors.workspace = true
+description = "Caching datastructures for re_query"
+edition.workspace = true
+homepage.workspace = true
+include.workspace = true
+license.workspace = true
+publish = true
+readme = "README.md"
+repository.workspace = true
+rust-version.workspace = true
+version.workspace = true
+
+[package.metadata.docs.rs]
+all-features = true
+
+
+[features]
+default = []
+
+[dependencies]
+# Rerun dependencies:
+re_log_types.workspace = true
+re_query.workspace = true
+re_types_core.workspace = true
+
+# External dependencies:
+ahash.workspace = true
+document-features.workspace = true
+itertools.workspace = true
+thiserror.workspace = true
+
+
+[dev-dependencies]
+re_log_types = { workspace = true, features = ["testing"] }
+
+criterion.workspace = true
+mimalloc.workspace = true
+similar-asserts.workspace = true
+
+
+[lib]
+bench = false
+
+
+[[bench]]
+name = "flat_vec_deque"
+harness = false