add setting for client to update wireguard port.

[elfkuzco]

Changes

• make wireguard port configurable in case client wants to use a different port. Working on the ProtonVPN config downloader, I realized that the hard-coded port of 51820 didn't have to be fixed.
• use better type annotations for generator function - fetch_tests
• show error message on Docker APIError

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 69.66%. Comparing base (0c088e1) to head (dffca52).
Report is 2 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main      #46   +/-   ##
=======================================
  Coverage   69.66%   69.66%           
=======================================
  Files          30       30           
  Lines         946      946           
  Branches       93       93           
=======================================
  Hits          659      659           
  Misses        267      267           
  Partials       20       20           

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

[rgaudin]

LGTM