core/rawdb: inspect database in parallel

[jsvisa]

db inspect on the full database currently takes 30min+, because the db iterate was run in one thread, propose to split the key-space to 256 sub range, and assign them to the worker pool to speed up.

After the change, the time of running db inspect --workers 16 reduced to 10min(the keyspace is not evenly distributed).

[rjl493456442]

Test it on my partial sync'd sepolia node, 3 minutes to traverse the key value store with 124GB data.

INFO [09-01|10:49:05.154] Inspecting database                      count=1,520,828,429 size=124.31GiB elapsed=3m4.001s
INFO [09-01|10:49:15.033] Opened ancient database                  database=/home/gary/hdd/sepolia-archive/ancient/state readonly=true

+-----------------------+-----------------------------+------------+------------+
|       DATABASE        |          CATEGORY           |    SIZE    |   ITEMS    |
+-----------------------+-----------------------------+------------+------------+
| Key-Value store       | Headers                     | 52.21 MiB  |      90001 |
| Key-Value store       | Bodies                      | 10.79 GiB  |      90001 |
| Key-Value store       | Receipt lists               | 3.38 GiB   |      90001 |
| Key-Value store       | Difficulties (deprecated)   | 0.00 B     |          0 |
| Key-Value store       | Block number->hash          | 3.60 MiB   |      90001 |
| Key-Value store       | Block hash->number          | 196.60 MiB |    5028001 |
| Key-Value store       | Transaction index           | 4.16 GiB   |  124066228 |
| Key-Value store       | Log index filter-map rows   | 0.00 B     |          0 |
| Key-Value store       | Log index last-block-of-map | 0.00 B     |          0 |
| Key-Value store       | Log index block-lv          | 0.00 B     |          0 |
| Key-Value store       | Log bloombits (deprecated)  | 0.00 B     |          0 |
| Key-Value store       | Contract codes              | 5.14 GiB   |     818148 |
| Key-Value store       | Hash trie nodes             | 0.00 B     |          0 |
| Key-Value store       | Path trie state lookups     | 175.93 MiB |    4499539 |
| Key-Value store       | Path trie account nodes     | 3.20 GiB   |   28212407 |
| Key-Value store       | Path trie storage nodes     | 23.95 GiB  |  238211659 |
| Key-Value store       | Path state history indexes  | 59.02 GiB  |  955373200 |
| Key-Value store       | Verkle trie nodes           | 0.00 B     |          0 |
| Key-Value store       | Verkle trie state lookups   | 0.00 B     |          0 |
| Key-Value store       | Trie preimages              | 61.92 MiB  |     882562 |
| Key-Value store       | Account snapshot            | 1.27 GiB   |   20498673 |
| Key-Value store       | Storage snapshot            | 12.63 GiB  |  175752705 |
| Key-Value store       | Beacon sync headers         | 2.08 GiB   |    3582837 |
| Key-Value store       | Clique snapshots            | 0.00 B     |          0 |
| Key-Value store       | Singleton metadata          | 2.35 KiB   |         13 |
| Ancient store (Chain) | Bodies                      | 105.98 GiB |    4938001 |
| Ancient store (Chain) | Receipts                    | 13.28 GiB  |    4938001 |
| Ancient store (Chain) | Headers                     | 1.85 GiB   |    4938001 |
| Ancient store (Chain) | Hashes                      | 178.95 MiB |    4938001 |
| Ancient store (State) | History.Meta                | 339.00 MiB |    4499538 |
| Ancient store (State) | Account.Index               | 5.03 GiB   |    4499538 |
| Ancient store (State) | Storage.Index               | 11.76 GiB  |    4499538 |
| Ancient store (State) | Account.Data                | 4.24 GiB   |    4499538 |
| Ancient store (State) | Storage.Data                | 1.98 GiB   |    4499538 |
+-----------------------+-----------------------------+------------+------------+
|                                    TOTAL            | 270.71 GIB | 1557285977 |