Improve the logic & reflection of Nested Steps execution results in Allure report

[cherevachy]

Currently step <When the condition {condition_expression} is true I do> is displayed as "green" in Allure report in the following cases:

1. condition expression is incorrect
2. condition expression is correct & failed
   This can be misleading as gives no details on actual condition status as well as does not highlight the fact that the nested steps were skippsed

The proposed improvement:
For case 1) - The condition step should be failed with the message that condition_expression is invalid; it should be mentioned that the nested steps execution was skipped
For case 2) - - The condition step should still be passed, but it should be mentioned that the nested steps execution was skipped due to failed condition