feat: add @QaseTags annotation for assigning tags to test cases

[gibiw]

Summary

• Added @QaseTags({"smoke", "regression"}) annotation for Java test methods (JUnit4, JUnit5, TestNG)
• Added @QaseTags=smoke,regression Gherkin tag for Cucumber scenarios (v3-v7)
• Tags are mapped to ResultCreateFields.tags as comma-separated string in API v2
• Also supports @QaseFields(@Field(name = "tags", value = "smoke,regression")) as alternative
• Bumped version to 4.1.50

Ref: qase-csharp PR #53

Changes

Core (qase-java-commons)

• New annotation: @QaseTags (method-level, String[] value())
• New field: TestResult.tags (List<String>, initialized empty)
• IntegrationUtils.getQaseTags() — reflection-based extraction
• CucumberUtils.getCaseTags() — Gherkin tag parsing (@QaseTags= with = delimiter)
• TestResultBuilder — tags extraction in all 3 entry points (fromMethod, fromAnnotationReader, fromCucumber)
• ApiClientV2.convertResult() — maps tags to fields.setTags() with deduplication; handles "tags" key from fields map

Tests

• 13 new unit tests (7 in TestResultBuilderTest, 6 in CucumberUtilsTest)
• Updated expected YAML files for integration tests
• Updated example tests for all frameworks

Documentation

• Changelog entry for 4.1.50
• Usage guide section "Adding Tags" in JUnit5 docs
• Features list updated in JUnit4, JUnit5, TestNG, Cucumber 7 READMEs

Test plan

• All 301 unit tests pass (mvn test -pl qase-java-commons)
• Full project compiles (mvn compile)
• Run integration tests with reporters-validator
• Verify tags appear in Qase TestOps after reporting