Adds python interface to triangle.

[LolaSegura]

🎉 New feature

Goes on top of #220
Related to #101 #210

Summary

Adds Python interface for Triangle.

Related issues and notes

• To offer the operator[] functionality in python, the class had to be extended in the interface file (.i file) adding getitem(), calling the operator[] inside.

Checklist

• Signed all commits for DCO
• Added tests
• Added example and/or tutorial
• Updated documentation (as needed)
• Updated migration guide (as needed)
• codecheck passed (See contributing)
• All tests passed (See test coverage)
• While waiting for a review on your PR, please help review another open pull request to support the maintainers

Note to maintainers: Remember to use Squash-Merge

[codecov]

Codecov Report

Merging #231 (5bca988) into ign-math6 (3ea6229) will not change coverage.
The diff coverage is n/a.

❗ Current head 5bca988 differs from pull request most recent head d1fbba1. Consider uploading reports for the commit d1fbba1 to get more accurate results

@@            Coverage Diff             @@
##           ign-math6     #231   +/-   ##
==========================================
  Coverage      99.21%   99.21%           
==========================================
  Files             65       65           
  Lines           6089     6089           
==========================================
  Hits            6041     6041           
  Misses            48       48           

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[francocipollone]

Update this branch now that #220 got merged --> Done

[francocipollone]

I've just fixed conflicts.

[chapulina]

Looks great!