support create partition table for non REST catalog

[FANNG1]

The type of partition_spec in TableCreation is UnboundPartitionSpec, it's more dedicated to REST catalog, for non REST catalog seems more general to use PartitionSpec type. like

    let p = PartitionSpecBuilder::new(&table_schema)
        .add_partition_field("a", "bucket_a", Transform::Bucket(16))
        .add_partition_field("b", "b", Transform::Identity)
        .build()
        
    TableCreation::builder()
         .name(table_id.name.clone())
         .schema(table_schema.clone())
         .partition_spec(p).build()

[liurenjie1024]

Thanks @FANNG1 for contribution. I've left comments in your pr.