Feature Request

Describe your feature request related problem:

Part of #325.
For a good experience, allow users to call PITR's building block features in SQL

Task List

• Implement memory control. ticdc#736 Support Management TiCDC by SQL/API
• BR support generates rollback SQL from TiCDC log backup in SQL
• BR support restores data from TiCDC log backup.
• BR support generates differential backup with log backup in SQL? (Need to consider TiDB's disk requirements)

Workload estimation(person-day)

• Design+Develop: 30
• QA: 15
• Document: 5