[Feature] support iceberg rest catalog for iceberg compatibility

### Search before asking

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

### Motivation

For seamless integration of paimon-cdc with snowflake via apache polaris (which is a rest based iceberg catalog)

### Solution

_No response_

### Anything else?

_No response_

### Are you willing to submit a PR?

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

The issue targets paimon-cdc integration with Snowflake through Apache Polaris and an Iceberg REST catalog, but names no files, tests, or implementation plan. Start by locating the catalog and compatibility entry points, then review how REST catalog support would fit the existing design. Done means the requested integration works with Polaris and its compatibility is covered by tests.

Written by the indexing model from the issue text.