feature: Update e2e tests for a new napp (`kytos_stats`)

[gretelliz]

This is related to EP035

flow_stats will evolve to kytos_stats for kytos statistics and e2e tests need to be updated:

• Update the routes in the e2e test suite for flow_stats to kytos_stats.
• Include an e2e test for a new endpoint v1/table/stats using OvS.