MC-117: Create writer to send attribute sets and groups

| Q                    | A
| -------------------- | ---
| Bug fix?             | n
| New feature?         | y
| Specs pass?*         | y
| Checkstyle issues?** | n
| PMD issues?***       | n
| Fixed tickets        | MC-117 / MC-83
| Doc PR               | 
Should be on the AbstractWriter part. It's useless here if you call the parent.
Same for all writers.