Improve maven build process

The maven build process takes a lot of time as for any changes made, we need to build from the root.
We should try to make maven build allow us to run from any pinot-component to simplify the logic.

The issue names Maven, the repository root, and pinot-component modules but no specific files or tests. First inspect how the root Maven build discovers and builds components, then determine what prevents running it from an individual component. Done means changes can be built from any pinot-component without requiring a root build.

Written by the indexing model from the issue text.