Sort tests by estimated size and exception type

[IlyaMuravjov]

Description

Non-parametrized tests are now sorted within the cluster by their estimated size (the smaller the earlier).

Additionally, regardless of their size NPE tests are always placed after non-NPE tests.

How to test

Manual tests

Generate tests for the following class, tests should be properly sorted.

public class Lists { public static int sum(List<Integer> list) { int sum = 0; for (int i: list) sum += i; return sum; } public static <T> T getFirst(List<T> list) { return list.get(0); } }

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.