Encode causal timestamp in storage module for RawKV APIV2

[haojinming]

Development Task

Encode ts in storage module can benifit from following aspects:

1. Compatible with solution of issue: supporting using more efficient format for put/delete requests #12020
2. Resolved the rawkv cdc issue, that when propose failed, there may be dead lock in resolved_ts, which is currently resolved by dead lock detection in

   tikv/components/cdc/src/endpoint.rs

   Line 913 in 7824699

   fn handle_raw_outlier_regions(

3. Helpful to implement stale read in rawkv, ref : Stale read for rawkv with read ts rfcs#96.

To implement this, we need three PRs to achieve it:

• Let raw modify interface in storage use scheduler instead of grpc thread, including raw_put, raw_delete, raw_batch_put, raw_batch_delete, raw_batch_put_atomic, raw_batch_delete_atomic, raw_compare_and_swap_atomic. rawkv: Reuse scheduler worker pool for raw modify command #13286
• Get causal ts from CausalTsProvider and append ts to key in storage, remove pre_propose observer in CausalObserver. Use ConcurrencyManager to lock on-road key instead of cdc raw lock heap. rawkv: Encode ts to apiv2 key in storage instead of causal observer #13326
• Remove dead lock detection and move to tikv-cdc and raw resolved_ts related code. cdc: Clean rawkv resolved ts code #13496

[haojinming]

All PRs are merged in master branch. But there is still one issue unfixed: #13502.