## What changes were proposed in this pull request?
This PR adds `spark_partition_id` virtual column function in SparkR for API parity.
The following is just an example to illustrate a SparkR usage on a partitioned parquet table created by `spark.range(10).write.mode("overwrite").parquet("/tmp/t1")`.
```r
> collect(select(read.parquet('/tmp/t1'), c('id', spark_partition_id())))
id SPARK_PARTITION_ID()
1 3 0
2 4 0
3 8 1
4 9 1
5 0 2
6 1 3
7 2 4
8 5 5
9 6 6
10 7 7
```
## How was this patch tested?
Pass the Jenkins tests (including new testcase).
Author: Dongjoon Hyun <dongjoon@apache.org>
Closes#13768 from dongjoon-hyun/SPARK-16053.
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