feat: Articulation Points algorithm

[guyroznb]

Description of Change

1. adding new feature - articulation point algorithm. In a graph, a vertex is called an articulation point if removing it and all the edges associated with it results in the increase of the number of connected components in the graph. For example consider the graph given in following figure.
2. moving the GraphRep struct from Graph.c to Graph.h

References

Checklist

• Added description of change
• Added file name matches File name guidelines
• Added tests and example, test must pass
• Relevant documentation/comments is changed or added
• PR title follows semantic commit guidelines
• Search previous suggestions before making a new one, as yours may be a duplicate.
• I acknowledge that all my contributions will be made under the project's license.

[kvedala]

Duplicate of #645. Do not create multiple pull-requests for the same code.

[guyroznb]

hi @kvedala, I added descriptions in the code.

[github-actions]

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[github-actions]

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