[SPARK-17153][SQL] Should read partition data when reading new files in filestream without globbing

## What changes were proposed in this pull request?

When reading file stream with non-globbing path, the results return data with all `null`s for the
partitioned columns. E.g.,

    case class A(id: Int, value: Int)
    val data = spark.createDataset(Seq(
      A(1, 1),
      A(2, 2),
      A(2, 3))
    )
    val url = "/tmp/test"
    data.write.partitionBy("id").parquet(url)
    spark.read.parquet(url).show

    +-----+---+
    |value| id|
    +-----+---+
    |    2|  2|
    |    3|  2|
    |    1|  1|
    +-----+---+

    val s = spark.readStream.schema(spark.read.load(url).schema).parquet(url)
    s.writeStream.queryName("test").format("memory").start()

    sql("SELECT * FROM test").show

    +-----+----+
    |value|  id|
    +-----+----+
    |    2|null|
    |    3|null|
    |    1|null|
    +-----+----+

## How was this patch tested?

Jenkins tests.

Author: Liang-Chi Hsieh <simonh@tw.ibm.com>
Author: Liang-Chi Hsieh <viirya@gmail.com>

Closes #14803 from viirya/filestreamsource-option.