refactor(query): first check privilege in SystemEngine get_full_data

[TCeason]

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Summary

Optimize:

in system table engine , we can only get database that current user can be visibility.

Tests

• [ ] Unit Test
• [x] Logic Test
• [ ] Benchmark Test
• [ ] No Test - Explain why

Type of change

• [ ] Bug Fix (non-breaking change which fixes an issue)
• [ ] New Feature (non-breaking change which adds functionality)
• [ ] Breaking Change (fix or feature that could cause existing functionality not to work as expected)
• [ ] Documentation Update
• [ ] Refactoring
• [x] Performance Improvement
• [ ] Other (please describe):

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This change is 

[TCeason]

Cc @wubx You can test show columns with this optimize.