Fix the way of setting static final fields

[sergeypospelov]

Description

Merged withAccessibility and withRemovedFinalModifer function in ReflectionUtil.kt, so it won't be possible to get the wrong cached FieldAccessor field, if we use our function.

Fixes #458

Type of Change

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

How Has This Been Tested?

Manual Scenario

Repeated To Reproduce section from #458. Tests are successfully generated.

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
• All tests pass locally with my changes

[Damtev]

Do we really need this dependency on the utbot-sample? Please consider the idea of moving the test class to the "utbot-core" module.