Add branching analyzer tests

[github-actions[bot]]

Package	Line Rate	Branch Rate	Complexity	Health
LivingDocumentation.Abstractions	100%	100%	6	✔
LivingDocumentation.Analyzer	68%	61%	254	➖
LivingDocumentation.Descriptions	98%	97%	268	✔
LivingDocumentation.Extensions	100%	100%	22	✔
LivingDocumentation.Json	100%	75%	14	✔
LivingDocumentation.RenderExtensions	68%	80%	133	➖
LivingDocumentation.Statements	100%	100%	16	✔
Summary	81% (698 / 863)	78% (448 / 574)	713	✔

[coveralls]

Pull Request Test Coverage Report for Build 1849062735

• 6 of 7 (85.71%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+4.4%) to 79.749%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/LivingDocumentation.Analyzer/Analyzers/BranchingAnalyzer.cs	6	7	85.71%
<!--	Total:	6	7	85.71%	-->

Totals
Change from base Build 1847223173:	4.4%
Covered Lines:	698
Relevant Lines:	863

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💛 - Coveralls