Feature Request

Describe your feature request related problem:

Currently, BR only support three modes of backup:

• Full backup
• One DB backup
• One Table backup
  And we may need support more general way of backup like black-white list on DBs or Tables,

Describe the feature you'd like:

1. Add config about black-white list, like DM black-white list
2. use simple wildcard in command.
3. other ideas

Describe alternatives you've considered:

Teachability, Documentation, Adoption, Migration Strategy: