Update cop rpc execution info (pingcap#19995)

sql-statements/sql-statement-explain-analyze.md

@@ -91,7 +91,7 @@ EXPLAIN ANALYZE SELECT * FROM t1;
 +-------------------+----------+---------+-----------+---------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+--------------------------------+-----------+------+
 | id                | estRows  | actRows | task      | access object | execution info                                                                                                                                                                                                                            | operator info                  | memory    | disk |
 +-------------------+----------+---------+-----------+---------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+--------------------------------+-----------+------+
-| TableReader_5     | 10000.00 | 3       | root      |               | time:278.2µs, loops:2, cop_task: {num: 1, max: 437.6µs, proc_keys: 3, rpc_num: 1, rpc_time: 423.9µs, copr_cache_hit_ratio: 0.00}                                                                                                          | data:TableFullScan_4           | 251 Bytes | N/A  |
+| TableReader_5     | 10000.00 | 3       | root      |               | time:278.2µs, loops:2, cop_task: {num: 1, max: 437.6µs, proc_keys: 3, copr_cache_hit_ratio: 0.00}, rpc_info:{Cop:{num_rpc:1, total_time:423.9µs}}                                                                                         | data:TableFullScan_4           | 251 Bytes | N/A  |
 | └─TableFullScan_4 | 10000.00 | 3       | cop[tikv] | table:t1      | tikv_task:{time:0s, loops:1}, scan_detail: {total_process_keys: 3, total_process_keys_size: 111, total_keys: 4, rocksdb: {delete_skipped_count: 0, key_skipped_count: 3, block: {cache_hit_count: 0, read_count: 0, read_byte: 0 Bytes}}} | keep order:false, stats:pseudo | N/A       | N/A  |
 +-------------------+----------+---------+-----------+---------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+--------------------------------+-----------+------+
 2 rows in set (0.00 sec)
@@ -120,15 +120,15 @@ The execution information of the `Batch_Point_Get` operator is similar to that o
 The execution information of a `TableReader` operator is typically as follows:
 
 ```
-cop_task: {num: 6, max: 1.07587ms, min: 844.312µs, avg: 919.601µs, p95: 1.07587ms, max_proc_keys: 16, p95_proc_keys: 16, tot_proc: 1ms, tot_wait: 1ms, rpc_num: 6, rpc_time: 5.313996 ms, copr_cache_hit_ratio: 0.00}
+cop_task: {num: 6, max: 1.07587ms, min: 844.312µs, avg: 919.601µs, p95: 1.07587ms, max_proc_keys: 16, p95_proc_keys: 16, tot_proc: 1ms, tot_wait: 1ms, copr_cache_hit_ratio: 0.00}, rpc_info:{Cop:{num_rpc:6, total_time:5.313996ms}}
 ```
 
 - `cop_task`: Contains the execution information of `cop` tasks. For example:
     - `num`: The number of cop tasks.
     - `max`, `min`, `avg`, `p95`: The maximum, minimum, average, and P95 values of the execution time consumed for executing cop tasks.
     - `max_proc_keys` and `p95_proc_keys`: The maximum and P95 key-values scanned by TiKV in all cop tasks. If the difference between the maximum value and the P95 value is large, the data distribution might be imbalanced.
-    - `rpc_num`, `rpc_time`: The total number and total time consumed for `Cop` RPC requests sent to TiKV.
     - `copr_cache_hit_ratio`: The hit rate of Coprocessor Cache for `cop` task requests.
+- `rpc_info`: The total number and total time of RPC requests sent to TiKV aggregated by request type.
 - `backoff`: Contains different types of backoff and the total waiting time of backoff.
 
 ### Insert