Starting code for c++ backend of trees

[Kishan-Ved]

References to other Issues or PRs or Relevant literature

Starting code for #550. This is more like a template.

Brief description of what is fixed or changed

This is some starting code for the trees backend. Honestly, some of this was written by ChatGPT, although I have understood and ensured that most of it is correct and necessary. Please check this and let me know if it is correct, so I can proceed with this. Also, please let me know what part has to be included in header file etc.

[Kishan-Ved]

This might not seem like a lot of code addition, but I prefer making small PRs and getting code verified atleast at the start.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 97.552%. Comparing base (ec0b015) to head (cf62fc5). Report is 1 commits behind head on main.

:exclamation: Current head cf62fc5 differs from pull request most recent head 8ec0296. Consider uploading reports for the commit 8ec0296 to get more accurate results

Additional details and impacted files

@@            Coverage Diff            @@
##              main      #551   +/-   ##
=========================================
  Coverage   97.552%   97.552%           
=========================================
  Files           34        34           
  Lines         4331      4331           
=========================================
  Hits          4225      4225           
  Misses         106       106           

[Kishan-Ved]

Gentle Reminder, please check this.

[czgdp1807]

Looks duplicate of #555. Closing this in favour of #555.