Remove public modifiers from test classes and methods

[ic0ns]

Summary

• Removed unnecessary public modifiers from test classes and methods following JUnit 5 best practices
• Updated 78 test files (4 files already had proper modifiers)
• No functional changes - only visibility modifiers were updated

Changes

• Test class declarations now use package-private visibility
• Test methods (@test annotated) now use package-private visibility
• Lifecycle methods (@beforeeach, @AfterEach, @BeforeAll, @afterall) now use package-private visibility
• Inner classes and helper methods now use appropriate visibility
• Kept public modifiers only where required for overriding public methods from parent classes/interfaces

Test plan

• Run mvn test to ensure all 782 tests still pass
• Verify code compiles successfully with mvn test-compile
• All tests pass without any failures