Support traffic statements in parser

[djshow832]

Support SQL to capture and replay traffic using TiProxy. This is a parser issue.

TRAFFIC CAPTURE TO "/tmp/traffic" DURATION="1h" ENCRYPTION_METHOD="aes256-ctr" COMPRESS=false
TRAFFIC REPLAY FROM "/tmp/traffic" USER="u1" PASSWORD="123456" SPEED=1.0
CANCEL TRAFFIC JOBS
SHOW TRAFFIC JOBS

Refer to similar statements:

PLAN REPLAYER DUMP EXPLAIN select * from t;
PLAN REPLAYER LOAD 'file_name';
PLAN REPLAYER CAPTURE 'sql_digest' '*';
SELECT * FROM mysql.plan_replayer_task;    # query plan replayer tasks

BACKUP DATABASE `test` TO 's3://backup/' COMPRESSION_LEVEL=3 ENCRYPTION_METHOD='aes256';
SHOW BACKUPS;
RESTORE DATABASE * FROM 's3://backup/'  CONCURRENCY = 64 CHECKSUM = FALSE;
SHOW RESTORES;
KILL 5857102839209263511;   # kill backup/restore job
SHOW BR JOB 1;
CANCEL BR JOB 1;

IMPORT INTO t FROM '/path/to/file.csv' WITH SKIP_ROWS=1 THREAD=10;
SHOW IMPORT JOBS;
CANCEL IMPORT JOB 1;

ADMIN CANCEL DDLS;
ADMIN SHOW DDL JOBS;

SET @@global.tidb_ttl_job_enable = OFF;     # cancel all ttl jobs
SELECT * FROM mysql.tidb_ttl_table_status;    # query ttl jobs