saving application components in tests: choose non-deprecated storage
(cherry picked from commit 474ede8)
EDU-300 Incomplete test for lesson 10/ task 1
(cherry picked from commit b063104)
english proofreading and readability from user
(cherry picked from commit 7ae861b)
fixed EDU-282 Run tests as cancelable background task
(cherry picked from commit 3ac3c9e)
fixed assert
(cherry picked from commit f8fc14f)
EDU-299 Incomplete test for lesson 9  task 1
(cherry picked from commit 77d40b2)
fixed some problems with checker
(cherry picked from commit 2e67229)
EDU-297 incomplete test for lesson 6 task 3
(cherry picked from commit 999509f)
synchronized test_helper template with actual test_helper
(cherry picked from commit ca3d946)
EDU-296 incomplete test for lesson 2 task 5
(cherry picked from commit d27ade6)
EDU-272 PyCharm lesson 3.10 confusing result validation
(cherry picked from commit 9e1160c)
EDU-264 In run_common_tests default error text is always shown
(cherry picked from commit 7968038)
EDU-293 False positive result in "access_variable.py" using `==´ as opposed to `=´ in line 11
(cherry picked from commit 7be7589)
EDU-281 Incomplete test for task: lesson 9 task 2
(cherry picked from commit 67b953b)
EDU-283 Wrong message for test fail: lesson 10 task 1
(cherry picked from commit 84f7ccc)
fixed possible answer for lesson6/task3
(cherry picked from commit 037a49d)
Merge remote-tracking branch 'origin/139' into 139