Improve test class names in test-bundles

[bytinbit]

Test classes are defined in yaml bundles like this:

- test_class: TestNapalmBgpNeighbors
  test_data:
    - host: R1
      peer: 1.2.3.4
      is_up: false

From a usability standpoint it would be good to improve the name of the test class, currently, the backend library is included in the name and could be omitted. Example:

- test_class: TestBgpNeighbors
  test_data:
    - host: R1
      peer: 1.2.3.4
      is_up: false

Goal: Omit the backend library mentioned in the test_class name of a YAML test bundle.

Do not forget to:

• Update the docs
• Fix names in index.py