Remove java/main from the path to the generated tests

[mmvpm]

Description

Now we have substring java/main in the path to the generated (with utbot-gradle or utbot-maven) tests.

But these words go into the test package name, and that's not what we want. Therefore, it is necessary to remove source root name and language folder from the path.

To Reproduce

Run test generation using utbot-gradle or utbot-maven and look at the path to generated tests.