YARN module has nonstandard structure which cause compile error In IntelliJ

The YARN module has nonstandard path structure like:

${SPARK_HOME}
  |--yarn
     |--alpha (contains yarn api support for 0.23 and 2.0.x)
     |--stable (contains yarn api support for 2.2 and later)
     |     |--pom.xml (spark-yarn)
     |--common (Common codes not depending on specific version of Hadoop)
     |--pom.xml (yarn-parent)

When we use maven to compile yarn module, maven will import 'alpha' or 'stable' module according to profile setting.
And the submodule like 'stable' use the build propertie defined in yarn/pom.xml to import common codes to sourcePath.
It will cause IntelliJ can't directly recognize sources in common directory as sourcePath.

I thought we should change the yarn module to a unified maven jar project,
and add specify different version of yarn api via maven profile setting.

It will resolve the compile error in IntelliJ and make the yarn module more simple and clear.