[SPARK-18939][SQL] Timezone support in partition values.

## What changes were proposed in this pull request?

This is a follow-up pr of #16308 and #16750.

This pr enables timezone support in partition values.

We should use `timeZone` option introduced at #16750 to parse/format partition values of the `TimestampType`.

For example, if you have timestamp `"2016-01-01 00:00:00"` in `GMT` which will be used for partition values, the values written by the default timezone option, which is `"GMT"` because the session local timezone is `"GMT"` here, are:

```scala
scala> spark.conf.set("spark.sql.session.timeZone", "GMT")

scala> val df = Seq((1, new java.sql.Timestamp(1451606400000L))).toDF("i", "ts")
df: org.apache.spark.sql.DataFrame = [i: int, ts: timestamp]

scala> df.show()
+---+-------------------+
|  i|                 ts|
+---+-------------------+
|  1|2016-01-01 00:00:00|
+---+-------------------+

scala> df.write.partitionBy("ts").save("/path/to/gmtpartition")
```

```sh
$ ls /path/to/gmtpartition/
_SUCCESS			ts=2016-01-01 00%3A00%3A00
```

whereas setting the option to `"PST"`, they are:

```scala
scala> df.write.option("timeZone", "PST").partitionBy("ts").save("/path/to/pstpartition")
```

```sh
$ ls /path/to/pstpartition/
_SUCCESS			ts=2015-12-31 16%3A00%3A00
```

We can properly read the partition values if the session local timezone and the timezone of the partition values are the same:

```scala
scala> spark.read.load("/path/to/gmtpartition").show()
+---+-------------------+
|  i|                 ts|
+---+-------------------+
|  1|2016-01-01 00:00:00|
+---+-------------------+
```

And even if the timezones are different, we can properly read the values with setting corrent timezone option:

```scala
// wrong result
scala> spark.read.load("/path/to/pstpartition").show()
+---+-------------------+
|  i|                 ts|
+---+-------------------+
|  1|2015-12-31 16:00:00|
+---+-------------------+

// correct result
scala> spark.read.option("timeZone", "PST").load("/path/to/pstpartition").show()
+---+-------------------+
|  i|                 ts|
+---+-------------------+
|  1|2016-01-01 00:00:00|
+---+-------------------+
```

## How was this patch tested?

Existing tests and added some tests.

Author: Takuya UESHIN <ueshin@happy-camper.st>

Closes #17053 from ueshin/issues/SPARK-18939.