Add a test suite for `pathfinder` endpoints

[viniarck]

Currently pathfinder only has this POST /v2 endpoint. pathfinder is being indirectly tested since mef_eline depends on it for dynamic paths. However, we also need an individual test suite to validate changes and avoid regressions on pathfinder individually, this also helps to isolate and understand why a test might be failing.

You need to add a test case testing the following parameters (the linked API documentation explain what each parameter does, also check out EP023-2 blueprint for extra informaiton about them):

• undesired_links
• spf_attribute
• spf_max_path_cost
• mandatory_metrics
• flexible_metrics
• minimum_flexible_hits

[viniarck]

The recommended topology should also add the metadata during the test suite setup you can either use the MultiConnectedTopo and plan for adding metadata like these ones (here's an example of how to add metadata):

or use AmlightTopo with an equivalent kytos-amlight-topo-init.sh. MultiConnectedTopo is a smaller topology and easier to plan for the test cases with these attributes.