feat(invoices): add support for copying invoice to other storage

[nijel]

Proposed changes

Checklist

• Lint and unit tests pass locally with my changes.
• I have added tests that prove my fix is effective or that my feature works.
• I have added documentation to describe my feature.
• I have squashed my commits into logic units.
• I have described the changes in the commit messages.

Other information

[codecov]

Codecov Report

Attention: Patch coverage is 16.66667% with 5 lines in your changes missing coverage. Please review.

Project coverage is 82.20%. Comparing base (2347b3d) to head (6022dc8).
Report is 1 commits behind head on main.

✅ All tests successful. No failed tests found.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2267      +/-   ##
==========================================
- Coverage   82.30%   82.20%   -0.11%     
==========================================
  Files          35       35              
  Lines        3792     3798       +6     
  Branches      354      355       +1     
==========================================
+ Hits         3121     3122       +1     
- Misses        539      543       +4     
- Partials      132      133       +1