Improve focus rule

[nunnatsa]

Description

1. Forbid also the usage of the Focus individual spec, e.g.

   It("test something", Focus, func(){
       Expect(...)...
   })

2. Also forbid the FDescribeTable and the FEntry focused containers.

Type of change

Please delete options that are not relevant.

• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [x] This change requires a documentation update

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration

• [x] Added test case and related test data
• [x] Update the functional test

Checklist:

• [x] I have performed a self-review of my own code
• [x] I have made corresponding changes to the documentation
• [x] My changes generate no new warnings
• [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
• [x] Any dependent changes have been merged and published in downstream modules
• [x] I ran golangci-lint

@nunnatsa

[github-actions[bot]]

Pull Request Test Coverage Report for Build 5852308387

• 14 of 29 (48.28%) changed or added relevant lines in 2 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-1.0%) to 83.982%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
ginkgohandler/handler.go	2	17	11.76%
<!--	Total:	14	29	48.28%	-->

Totals
Change from base Build 5851657335:	-1.0%
Covered Lines:	928
Relevant Lines:	1105

---

💛 - Coveralls