feat: Add support for Multipath (two-path) descriptors

[tvpeter]

Description

This PR enables support for BIP389 multipath descriptors. It uses the existing external descriptor and verifies whether the provided descriptor is a multipath descriptor. If it is, a wallet will be created using the Wallet::create_from_two_path_descriptor() method. If not, the standard wallet creation logic will be applied.

Fixes #195

Replaces #238

Notes to the reviewers

• is_multipath_descriptor helper parses the descriptor and accepts only two-path multipath descriptors (external/internal).

Changelog notice

• Add support for BIP389 multipath descriptors

Checklists

All Submissions:

• I've signed all my commits
• I followed the contribution guidelines
• I ran cargo fmt and cargo clippy before committing

New Features:

• I've added tests for the new feature
• I've added docs for the new feature
• I've updated CHANGELOG.md

[codecov]

Codecov Report

❌ Patch coverage is 80.64516% with 12 lines in your changes missing coverage. Please review.
✅ Project coverage is 57.78%. Comparing base (e7223e5) to head (5afbc8a).
⚠️ Report is 3 commits behind head on master.

Files with missing lines	Patch %	Lines
src/persister.rs	74.07%	7 Missing ⚠️
src/utils/descriptors.rs	85.29%	5 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #309      +/-   ##
==========================================
+ Coverage   57.45%   57.78%   +0.32%     
==========================================
  Files          22       22              
  Lines        3695     3733      +38     
==========================================
+ Hits         2123     2157      +34     
- Misses       1572     1576       +4     

Flag	Coverage Δ
rust	57.78% <80.64%> (+0.32%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[sdmg15]

tACK 48b3314

[vadim-anfv]

tACK 5afbc8a

Verified locally that the invalid config is no longer saved.