[FEATURE] Delete datasource could delete session gracefully

[penghuo]

[vamsimanohar]

Requirements and tasks.

• Close all kinds of jobs related to the datasource when it is deleted.
• Proper warning message.
• Delegate to customer to delete all the related jobs instead of system doing it automatically.[one solution]
• How does Athena behave when we delete workgroup?
• Think through edge cases.
• CANCEL Session.