### What problem does this PR solve?
As title:
implement:
```
/api/v1/messages/search GET
/api/v1/messages GET
/api/v1/messages/<memory_id>:<message_id>/content GET
/api/v1/memories/<memory_id>/config GET
/api/v1/messages/<memory_id>:<message_id> PUT
```
### Type of change
- [x] New Feature (non-breaking change which adds functionality)