Improve scalastyle rules to detect spaces

[amahussein]

Signed-off-by: Ahmed Hussein (amahussein) [email protected]

Contributes to #1158

This pull request includes several changes to the core/scalastyle-config.xml file and updates to copyright years across multiple Scala files. Additionally, it includes minor code cleanups.

Updates to scalastyle-config.xml:

• Added new style checks:
  • SpacesAfterPlusChecker, SpacesBeforePlusChecker, WhitespaceEndOfLineChecker
  • DisallowSpaceBeforeTokenChecker, SingleSpaceBetweenRParenAndLCurlyBrace, OmitBracesInCase
  • NewLineAtEofChecker, SpaceAfterCommentStartChecker, EnsureSingleSpaceBeforeTokenChecker, EnsureSingleSpaceAfterTokenChecker
  • TokenChecker for println statements
  • Disabled checks: ParameterNumberChecker, PublicMethodsHaveTypeChecker, NonASCIICharacterChecker

[parthosa]

Thanks @amahussein for this change. Is there any standard scalastyle rule file that is accepted by the community (e.g. Spark repo)? Should we use that for standardization?

[amahussein]

Thanks @amahussein for this change. Is there any standard scalastyle rule file that is accepted by the community (e.g. Spark repo)? Should we use that for standardization?

Yes, we use the same scala style set by Spark.
The catch that Spark main branch has migrated to scala-2.13 already. I pulled some of the rules that are focused on code styling from https://github.com/apache/spark/blob/branch-3.5/scalastyle-config.xml . Blanks and comment styling were repeated problems we had in many PRs.
Later, we can pull other rules as we head toward supporting scala-2.13

[parthosa]

That makes sense. Thanks @amahussein for these changes. LGTME.