[Feature-wip](MySQL Load)Support cancel query for mysql load

[SaintBacchus]

Proposed changes

Issue Number: close #xxx

Problem summary

Notice some changes:

1. Support cancel query for mysql load
2. Change the thread pool for mysql load manager.
3. Fix sucret path check logic
4. Fix some doc error

Checklist(Required)

• [ ] Does it affect the original behavior
• [x] Has unit tests been added
• [x] Has document been added or modified
• [ ] Does it need to update dependencies
• [ ] Is this PR support rollback (If NO, please explain WHY)

Further comments

If this is a relatively large or complex change, kick off the discussion at [email protected] by explaining why you chose the solution you did and what alternatives you considered, etc...

[SaintBacchus]

run buildall

[SaintBacchus]

run buildall

[hello-stephen]

TeamCity pipeline, clickbench performance test result: the sum of best hot time: 35.62 seconds stream load tsv: 468 seconds loaded 74807831229 Bytes, about 152 MB/s stream load json: 40 seconds loaded 2358488459 Bytes, about 56 MB/s stream load orc: 76 seconds loaded 1101869774 Bytes, about 13 MB/s stream load parquet: 31 seconds loaded 861443392 Bytes, about 26 MB/s https://doris-community-test-1308700295.cos.ap-hongkong.myqcloud.com/tmp/20230307052949_clickbench_pr_109780.html

[SaintBacchus]

run p0

[SaintBacchus]

run buildall

[SaintBacchus]

run buildall

[SaintBacchus]

run buildall

[SaintBacchus]

run p0

[SaintBacchus]

run p0

[SaintBacchus]

run buildall

[SaintBacchus]

run buildall

[SaintBacchus]

run compile

[SaintBacchus]

run p0

[SaintBacchus]

run p0

[SaintBacchus]

run p1

[SaintBacchus]

run p1

[github-actions[bot]]

PR approved by at least one committer and no changes requested.

[github-actions[bot]]

PR approved by anyone and no changes requested.