[Improvement][Api] Add user permission validation logic to the getDatabases, getTables, and getTableColumns methods in DataSourceController

[njnu-seafish]

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• I had searched in the issues and found no similar feature requirement.

Description

Add user permission validation logic to the getDatabases, getTables, and getTableColumns methods in DataSourceController.

Are you willing to submit a PR?

• Yes I am willing to submit a PR!

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