druid java code formatting

currently we have an IntelliJ code formatter, an Eclipse code formatter and extras in checkstyle rules related to code formatting. all three of them are probably out of sync. Many times even after I format the code with IntelliJ, I still get formatting errors from checkstyle.

should we adopt some well known code formatting and tools , e.g. https://github.com/google/google-java-format and enforce them with checkstyle e.g. https://checkstyle.sourceforge.io/google_style.html that would be in sync and all the formatting rules are well written.

Related #1951

Compare the existing IntelliJ formatter, Eclipse formatter, and checkstyle formatting rules described in the issue. Review the proposed google-java-format and Google Checkstyle style, along with related issue #1951, before defining a consistent approach. Done means the project has an agreed formatting configuration and enforcement path that stays in sync.

Written by the indexing model from the issue text.