API Doc Namespace Edits + SimpleGraphImpl methods

[betochimas]

Increases consistency between the API docs and the namespace in which the method can be called from, reducing potential confusion. Ex: cugraph.centrality.betweenness_centrality.betweenness_centrality can now be found as cugraph.betweenness_centrality. Note: both are valid ways of calling the same method.

Includes methods and attributes of a graph object once data is loaded (from SimpleGraphImpl), such as number_of_vertices, has_edge, get_two_hops_neighbors, etc.

Ready for review.

[BradReesWork]

@gpucibot merge

[codecov-commenter]

Codecov Report

Merging #2086 (ca7e30b) into branch-22.04 (d947fb9) will increase coverage by 0.09%.
The diff coverage is 100.00%.

@@               Coverage Diff                @@
##           branch-22.04    #2086      +/-   ##
================================================
+ Coverage         73.54%   73.64%   +0.09%     
================================================
  Files               156      156              
  Lines             10316    10332      +16     
================================================
+ Hits               7587     7609      +22     
+ Misses             2729     2723       -6     

Impacted Files	Coverage Δ
...graph/cugraph/centrality/betweenness_centrality.py	89.65% <ø> (ø)
python/cugraph/cugraph/components/connectivity.py	95.00% <ø> (ø)
python/cugraph/cugraph/cores/core_number.py	100.00% <ø> (ø)
python/cugraph/cugraph/layout/force_atlas2.py	61.11% <ø> (+5.55%)	⬆️
python/cugraph/cugraph/linear_assignment/lap.py	71.42% <ø> (ø)
python/cugraph/cugraph/link_prediction/overlap.py	59.09% <ø> (ø)
python/cugraph/cugraph/link_prediction/sorensen.py	85.18% <ø> (ø)
...raph/structure/graph_implementation/simpleGraph.py	74.30% <ø> (ø)
python/cugraph/cugraph/structure/number_map.py	67.02% <ø> (ø)
python/cugraph/cugraph/utilities/utils.py	72.92% <100.00%> (+2.62%)	⬆️
... and 5 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update d947fb9...ca7e30b. Read the comment docs.