fix(cli): apply warning filter prior to execute_routing and add test coverage

[vaibhavsrv]

Related Issue / Discussion:

Fixes Issue #205

Changes:

• Modified: cli.py — Refactored CLI logic into a testable main(args_list=None) function and moved warnings.filterwarnings() prior to execute_routing().
• New: tests/test_cli.py — Added unit tests for CLI argument parsing, debug boolean handling, and call order assertions.

Further Details:

Summary:

• Motivation & Context: Currently, warnings.filterwarnings(args.filter_warnings) in cli.py is invoked after execute_routing() has already run. Consequently, any warnings issued during dataset loading or optimization bypass the specified filter setting.
• Before: Warning filter configuration occurred on the last line of cli.py after route execution finished.
• After: Warning filter configuration is executed immediately after argument parsing, prior to logging initialization and route optimization.

Dependencies:

No new external dependencies required.

PR Checklist:

In the context of this PR, I:

• have filled the 52North Contributor License Agreement and am waiting for feedback
• provide unit tests embedded in the WRT test framework (WeatherRoutingTool/tests) that allow the simple testing of the new/modified functionalities. All (previous and new) unit tests execute without new error messages.
• ensure that the code formatter runs without errors/warnings
• ensure that my changes follow the WRT’s guidelines for contributing at the time of the contribution