Corrected synthetic FuzzedMethodDescription for fuzzing thisInstance #892

[volivan239]

Description

Fuzzer uses synthetic methods to create instances of classes under test. However, their FuzzedMethodDescriptions lacked packageName. This lead to using reflection for instantiating package-private classes despite this could be done by constructors. This PR sets correct packageName and className to these descriptions.

Fixes #892

Type of Change

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

Manual Scenario

Launch plugin on example from #892 -- reflections are not used to instantiate class under test anymore.

Checklist (remove irrelevant options):

• The change followed the style guidelines of the UTBot project
• Self-review of the code is passed
• The change contains enough commentaries, particularly in hard-to-understand areas
• New documentation is provided or existed one is altered
• No new warnings
• New tests have been added
• All tests pass locally with my changes