Add MacOS GitHub actions

[Al2Klimov]

Is your feature request related to a problem? Please describe.

1. A Linux user builds something
2. GitHub actions: ✅
3. Mac user pulls it
4. Doesn't build

Examples:

• icinga_legacytimeperiod/dst unit test fails on Mac #9801
• Implement synchronous signal handling in umbrella/worker processes #10423 (review)
• Conversion of Function to Number possible on certain platforms #10459