SPARK-3962 Marked scope as provided for external projects.

Somehow maven shade plugin is set in infinite loop of creating effective pom.

Author: Prashant Sharma <prashant.s@imaginea.com>
Author: Prashant Sharma <scrapcodes@gmail.com>

Closes #2959 from ScrapCodes/SPARK-3962/scope-provided and squashes the following commits:

994d1d3 [Prashant Sharma] Fixed failing flume tests
270b4fb [Prashant Sharma] Removed most of the unused code.
bb3bbfd [Prashant Sharma] SPARK-3962 Marked scope as provided for external.

(cherry picked from commit 1c938413ba5579034675f1b4ea3b8fd0e47dd8d6)
Signed-off-by: Patrick Wendell <pwendell@gmail.com>