Generate thrift files by default at compilation time

Currently Hive does not generate thrift files within the main compilation task (mvn clean install -DskipTests), but it uses a separate profile (mvn clean install -Pthriftif -DskipTests -Dthrift.home=$thrift_path), and thrift-generated files are generally committed in VCS.

Other Apache projects like Parquet (https://github.com/apache/parquet-mr/blob/master/parquet-thrift/pom.xml) use a different approach, building all thrift files by default in the main compilation task.

In general, generated files should not be part of our VCS, only the "source" file should be (.thrift files here).

Including generated files in VCS is not only problematic because they are verbose and clog PR diffs, but they also generate a lot of conflicts (even when the changes over the thrift file can be merged automatically).

The ticket proposes to move the thrift files generation at compile time, remove the thrift-generated files from VCS, and add them to the "ignore" list.