Continuous downsampling

### Search before asking

- [X] I searched in the [issues](https://github.com/apache/iotdb/issues) and found nothing similar.

### Motivation

Is there any support for continuous downsampling, like it can be done with influx or timescale db ?
If no, it would be really nice to have feature.
If yes, thn I dont see any documentation, please update.

### Solution

_No response_

### Alternatives

Influx, timescaledb

### Are you willing to submit a PR?

- [ ] I'm willing to submit a PR!

No files, tests, or entry points are named. First inspect whether IoTDB already supports continuous downsampling and review its documentation; done means either documenting the existing behavior or defining and implementing the requested feature.

Written by the indexing model from the issue text.