Fix broken unit tests in progress_tests.rs — non-compiling references and wrong panic strings

[DeFiVC]

What

Two test functions in tests/unit/progress_tests.rs reference non-existent helper functions and expect panic messages that don't match the actual contract code. These tests will not compile.

Why

The tests test_complete_module_non_existent_module_panics and test_submit_quiz_score_without_enrollment_panics call setup_tracker(&env) and create_test_course(&env, &client, &course_id) which don't exist. The actual functions are setup_contract(&env) and create_test_course(&env, &client). Additionally, the expected panic strings don't match:

• Test expects "module does not belong to course" but contract panics with "module not found in course"
• Test expects "learner is not enrolled in course" but contract panics with "not enrolled"

Scope

• Fix function references to use existing helper functions
• Update #[should_panic(expected = "...")] attributes to match actual contract panic strings
• Verify tests compile and pass

Technical Context

• File: tests/unit/progress_tests.rs (lines ~673-699)
• Contract panic strings: progress-tracker/src/lib.rs (lines ~260, ~349)
• Actual helpers: setup_contract(&env), create_test_course(&env, &client) (2 args, no course_id)

Acceptance Criteria

• Both test functions compile successfully
• #[should_panic(expected = "...")] matches actual contract panic strings
• Tests pass with cargo test

[EstherIkechukwu]

I have gone through the description expect a pr in less than 12hrs