feat(chain): add walk_ancestors_from_root to TxGraph

[Dmenec]

Solves #2216

Description

Add walk_ancestors_from_root method to TxGraph, which mirrors the existing walk_ancestors but includes the root transaction in the iteration.

Notes to the reviewers

An alternative implementation would have been to make TxAncestors::new_include_root public directly, instead of adding a wrapper method on TxGraph. Not sure which approach is preferable here.

Changelog notice

Added

TxGraph::walk_ancestors_from_root

Checklists

All Submissions:

• I followed the contribution guidelines

New Features:

• I've added tests for the new feature
• I've added docs for the new feature

[codecov]

Codecov Report

❌ Patch coverage is 0% with 10 lines in your changes missing coverage. Please review.
✅ Project coverage is 77.55%. Comparing base (47556ab) to head (9789045).

Files with missing lines	Patch %	Lines
crates/chain/src/tx_graph.rs	0.00%	10 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2218      +/-   ##
==========================================
- Coverage   77.69%   77.55%   -0.14%     
==========================================
  Files          29       29              
  Lines        5801     5811      +10     
  Branches      271      271              
==========================================
  Hits         4507     4507              
- Misses       1223     1233      +10     
  Partials       71       71              

Flag	Coverage Δ
rust	77.55% <0.00%> (-0.14%)	⬇️

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