Create only required methods in UtUtils class

[EgorkaKulikov]

Description

Patch standard IntExamples a little, add the following constructor

 public IntExamples() {
        System.out.println("Vse ploxo!");
    }

Generate tests for max method.

This generation requires UtUtils class creation. But method createInstance only is required (and dependent getUnsafeInstance too).

Expected behavior

No other util methods should be located in UtUtils class (e.g. createArray - it is useless)
Actually, we see all supported in UtBot util methods in the generated code of util class.

Context

This behaviour seems to be the original design.
We select only required util methods when locate them in the test class, but having other util class we don't apply any filtering.

[alisevych]

@EgorkaKulikov
This behavior has also one more effect:
The UtUtils class is created only once.
It is recreated only if mocking support is needed (and it was not before).
Or if the new version of UtUtils class has come with new version of UnitTestBot.

[EgorkaKulikov]

I'm not going to start doing this task right now, just to note that we have this behavior and it seems to be controversial.