First Pass adding the newer DefaultTraversal

[JR-Morgan]

Added the DefaultTraversal that C# has been enjoying. (added by specklesystems/speckle-sharp#3327)

Reminder about what it is, its the new v3 de-facto rules to consume "convertible" objects in the tree.

It has been designed in a way that behaves for all intents and purposes, the same as the traversal logic in v2, but decoupled from the CanConvertToNative function that the old v2 function depended on.

Its what we should use when consuming objects in our v3 connectors.

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Tested with Blender connector (tho I'm not going to update blender until we do a v3)
I haven't done any unit tests for this DefaultTraversal, beyond the general ones for the GraphTraversal, since we don't have any in C#, but perhaps we should...

[linear]

CNX-860 Add GraphTraversal

[codecov]

Codecov Report

Attention: Patch coverage is 88.88889% with 1 line in your changes missing coverage. Please review.

Project coverage is 89.84%. Comparing base (9039515) to head (fb78e96).
Report is 16 commits behind head on v3-dev.

Files with missing lines	Patch %	Lines
src/specklepy/objects/graph_traversal/traversal.py	88.88%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           v3-dev     #367      +/-   ##
==========================================
+ Coverage   89.67%   89.84%   +0.17%     
==========================================
  Files         123      124       +1     
  Lines        6685     6729      +44     
==========================================
+ Hits         5995     6046      +51     
+ Misses        690      683       -7     

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