FEA Implement pruning using honest subsample data to fit the leaves

[adam2392]

Changes proposed in this pull request:

• Adds honest pruning, so no empty leaves occur within the HonestTreeClassifier

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[codecov[bot]]

Codecov Report

Attention: Patch coverage is 82.97872% with 8 lines in your changes missing coverage. Please review.

Project coverage is 80.11%. Comparing base (1d970b0) to head (a2bdf39). Report is 1 commits behind head on main.

Files	Patch %	Lines
treeple/tree/_honest_tree.py	82.60%	3 Missing and 5 partials :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #286 +/- ## ========================================== + Coverage 80.00% 80.11% +0.10% ========================================== Files 24 24 Lines 2221 2258 +37 Branches 411 418 +7 ========================================== + Hits 1777 1809 +32 - Misses 312 313 +1 - Partials 132 136 +4 ```

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