[Feature] Support Mosaic file format

[lxy-9602]

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• I searched in the issues and found nothing similar.

Motivation

Apache Paimon Java 2.0 supports Mosaic, a hybrid format designed for wide tables using column bucketing and parallel I/O. Paimon C++ cannot currently access tables using this format.

Solution

Add Mosaic support to the Paimon C++ file-format SPI:

• Register the mosaic file-format factory.
• Implement compatible schema, reader, writer, and statistics handling.
• Support column projection and Mosaic column-bucket metadata.
• Add C++ round-trip tests and Java-produced file compatibility tests.

Anything else?

We will also support formats such as Lance and Vortex in the future.

Are you willing to submit a PR?

• I'm willing to submit a PR!