Correct accessibily for package-private fields

[EgorkaKulikov]

Description

Consider the following scenario:

• we need to access package-private field
• it is declared in a class that is in the same package as a test class
• but the resolved variable type is represented in a class from another package

Thus we get compilation error. Here is a fix for it.

Fixes # (1677)

Type of Change

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

How Has This Been Tested?

Automated Testing

Run ContestEstimator with the following filter:

methodFilter = "spoon.support.reflect.code.CtAssignmentImpl.*"

Manual Scenario

Standard regression checks on package-private fields accessors.

Checklist (remove irrelevant options):

This is the author self-check list

• [+] The change followed the style guidelines of the UTBot project
• [+] Self-review of the code is passed
• [+] No new warnings