[Feature] Introduce statistics in Paimon

### Search before asking

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

### Motivation

1. Introduce partition statistics
2. Introduce column statistics

This is a big feature and should consider how to collect statistics efficiently if there are many files in a snapshot

### Solution

_No response_

### Anything else?

_No response_

### Are you willing to submit a PR?

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

Start by reviewing Paimon's snapshot and file-handling concepts, then clarify how partition and column statistics should be collected efficiently across many files in a snapshot. Done should be an agreed design for both kinds of statistics and their efficient collection.

Written by the indexing model from the issue text.