Description

Fixes #1992

Existing (old one) UtUtils class should be overwritten if any to get consistent generated code

How to test

Manual tests

1. Generate tests with old plugin version (2012.12 maybe) to get tests together with auxiliary UtUtils class
2. Update plugin
3. Generate tests again, existing UtUtils utility class with some new "throws" sections should be overwritten.

Self-check list

• I've set the proper labels for my PR (at least, for category and component).
• PR title and description are clear and intelligible.
• I've added enough comments to my code, particularly in hard-to-understand areas.
• The functionality I've repaired, changed or added is covered with automated tests.
• Manual tests have been provided optionally.
• The documentation for the functionality I've been working on is up-to-date.