Work on Tarjan's SCC algorithm

[ndcroos]

See #53

[codecov]

Codecov Report

Patch coverage: 98.85% and project coverage change: -0.17% ⚠️

Comparison is base (b8bd54e) 99.74% compared to head (35036c3) 99.57%.
Report is 5 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #78      +/-   ##
==========================================
- Coverage   99.74%   99.57%   -0.17%     
==========================================
  Files          23       25       +2     
  Lines        1158     1408     +250     
==========================================
+ Hits         1155     1402     +247     
- Misses          3        6       +3     

Files Changed	Coverage Δ
...b/algorithm/strongly_connected_components_test.cpp	98.57% <98.57%> (ø)
...aaflib/algorithm/strongly_connected_components.tpp	100.00% <100.00%> (ø)

... and 2 files with indirect coverage changes

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[bobluppes]

Thanks for working on this, LGTM!
I will commit the minor suggestions, after which I will merge the PR. So no need to address them.

[bobluppes]

[very minor]: Since we are not passing around the lambda in an interface, we can keep it a lambda closure rather than assigning it to a function object:

Suggested change

	// Lambda function for the strong connect traversal
	std::function<void(vertex_id_t)> strong_connect;
	strong_connect = [&](vertex_id_t vertex) {
	// Lambda function for the strong connect traversal
	const auto strong_connect = [&](vertex_id_t vertex) {

[bobluppes]

Ah, I see now why you did this, since the function object is used in the body the compiler needs to know the type. Reverted this change in 35036c3.

It might also be interesting to see if we can implement this in terms of the existing traversal algorithms in graph_traversal.h, but I will leave this for a follow up.