Fix error handling for invalid scenario names and numbers

[davidlin2k]

This pull request includes changes to improve error handling and validation for scenario names and numbers in the src/aqm-eval-suite/examples/aqm-eval-suite-runner.cc file. The most important changes include adding checks for invalid scenario numbers, providing user feedback for invalid inputs, and ensuring that scenario names are validated before execution.

Error handling improvements:

• Added a check to validate scenarioNumber and provide an error message if it is invalid, including a list of valid scenario numbers.
• Implemented a validation check for scenarioName to ensure it is either "All", "RttFairness", or a valid scenario name from the ScenarioNumberMapping. If invalid, an error message is displayed with a list of valid scenario names.

Code simplification:

• Replaced the iterator-based loop with a range-based for loop for better readability and modern C++ practices.

Example:

$ ./waf --run "aqm-eval-suite-runner --number=123"
Error: Invalid scenario number "123"
Valid scenario numbers are: "5.1.1" "5.1.2" "5.2" "5.3.1" "5.3.2" "5.4" "6" "8.2.2" "8.2.3" "8.2.4" "8.2.5" "8.2.6.1" "8.2.6.2"
Command ['/home/csc309/projects/ns-3-aqm-eval-suite/ns-3-dev-git/build/src/aqm-eval-suite/examples/ns3-dev-aqm-eval-suite-runner-debug', '--number=123'] exited with code 255