Print tags in gherkin-terminal-reporter output

[Nikolay-Chillev]

Summary

Display feature, scenario, and rule tags in the terminal reporter when using --gherkin-terminal-reporter with -v or -vv verbosity.

Closes #476

Changes

• Added _format_tags() helper function to format tag lists with @ prefix
• Modified -v mode output to show tags after feature, scenario, and rule names
• Modified -vv mode output to show tags after feature, scenario, and rule names
• Added 2 new tests verifying tag display in both verbosity modes

Example output

$ pytest --gherkin-terminal-reporter -v

Feature: Tagged feature @feature-tag
    Scenario: Tagged scenario @scenario-tag-1 @scenario-tag-2 PASSED

$ pytest --gherkin-terminal-reporter -vv

Feature: Tagged feature @feature-tag
    Scenario: Tagged scenario @scenario-tag-1 @scenario-tag-2
        Given there is a bar
        When the bar is accessed
        Then world explodes
    PASSED

Test plan

• All 16 existing + new reporter tests pass
• Tags displayed correctly in -v mode
• Tags displayed correctly in -vv mode
• Feature, scenario, and rule tags all supported
• No tags shown when none exist (no regression)