[SPARK-3560] Fixed setting spark.jars system property in yarn-cluster mode

Author: Victsm <victor.nju@gmail.com>
Author: Min Shen <mshen@linkedin.com>

Closes #2449 from Victsm/SPARK-3560 and squashes the following commits:

918405a [Victsm] Removed the additional space
4502a2a [Min Shen] [SPARK-3560] Fixed setting spark.jars system property in yarn-cluster mode.

(cherry picked from commit 832dff64ddb1240a4c8e22fcdc0e993cc8c808de)
Signed-off-by: Andrew Or <andrewor14@gmail.com>
[Minor Hot Fix] Move a line in SparkSubmit to the right place

This was introduced in #2449

Author: Andrew Or <andrewor14@gmail.com>

Closes #2452 from andrewor14/standalone-hot-fix and squashes the following commits:

d5190ca [Andrew Or] Put that line in the right place
[SPARK-3554] [PySpark] use broadcast automatically for large closure

Py4j can not handle large string efficiently, so we should use broadcast for large closure automatically. (Broadcast use local filesystem to pass through data).

Author: Davies Liu <davies.liu@gmail.com>

Closes #2417 from davies/command and squashes the following commits:

fbf4e97 [Davies Liu] bugfix
aefd508 [Davies Liu] use broadcast automatically for large closure