Add Windows and MacOS CI builds

[tzaeschke]

Add CI support for Windows and MacOS

---

This change is 

[codecov]

Codecov Report

Attention: Patch coverage is 75.00000% with 1 lines in your changes are missing coverage. Please review.

Project coverage is 77.52%. Comparing base (f6b54eb) to head (4dd5bdd).

❗ Current head 4dd5bdd differs from pull request most recent head bab3c0a. Consider uploading reports for the commit bab3c0a to get more accurate results

Files	Patch %	Lines
.../main/java/org/scion/internal/HostsFileParser.java	0.00%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##             master      #41      +/-   ##
============================================
- Coverage     77.54%   77.52%   -0.02%     
  Complexity      403      403              
============================================
  Files            26       26              
  Lines          1946     1949       +3     
  Branches        260      260              
============================================
+ Hits           1509     1511       +2     
  Misses          327      327              
- Partials        110      111       +1     

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