Add expand_logs ini option

[cidlik]

Motivation

In #721 expander for logs was added. Is some cases it is more convenient to expand all logs by default, e.g., if you have several tests with long logs and you need to find something.

Solution

I added ini option "expand_logs". If it is set to True, so all logs will be expanded by default.

Changes

• e6b8b5d - main change
• cee6448 - fix erros which were found by pre-commit
• e76199b - describe the feature in docs

[cidlik]

@BeyondEvil hello! Can you review this change, please?