[loader] renaming MainApp → DataLoader
[loading] FIX: some postal codes from test data are too long (changing limit: 10 → 12 chars)
[loading] added loading of all 3 data sets & time measuring
[loading, pom] DataLoader: jar packaging profile + DL fix: loading 2 biggest datasets only
[pom] eliminating maven warnings - specifying used plugin versions
[query] queries ready (version with spring-data-jpa @Query)