feat(anta): Added the test case for verify BGP peer group of the BGP IPv4 peer(s)

[vitthalmagadum]

Description

Verifies BGP peer group of the BGP IPv4 peer(s).

Expected Results
----------------
* Success: The test will pass if the peer group is correctly assigned to the BGP peer(s).
* Failure: The test will fail if the BGP peer group not correctly assigned or peer is not configured.

Fixes #810

Checklist:

• [X] My code follows the style guidelines of this project
• [X] I have performed a self-review of my code
• [X] I have run pre-commit for code linting and typing (pre-commit run)
• [ ] I have made corresponding changes to the documentation
• [X] I have added tests that prove my fix is effective or that my feature works
• [X] New and existing unit tests pass locally with my changes (tox -e testenv)

[sonarcloud[bot]]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[github-actions[bot]]

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