fix missing backtick in mysql keywords

[sjgllgh]

What is the purpose of the change

Fix the issue of not adding backticks for some MySQL keywords.

Related issues/PRs

Related issues: #4762

Brief change log

• Delete the file linkis-bml-server/src/main/resources/mapper/common/TaskMapper.xml;
• Add the file linkis-bml-server/src/main/resources/mapper/mysql/TaskMapper.xml;
• In the file mysql/TaskMapper.xml, backticks were added to the MySQL keyword "system".

Checklist

• [x] I have read the Contributing Guidelines on pull requests.
• [x] I have explained the need for this PR and the problem it solves
• [x] I have explained the changes or the new features added to this PR
• [x] I have added tests corresponding to this change
• [x] I have updated the documentation to reflect this change
• [x] I have verified that this change is backward compatible (If not, please discuss on the Linkis mailing list first)
• [x] If this is a code change: I have written unit tests to fully verify the new behavior.

[peacewong]

LGTM.