Setup cache server for overnigth jobs

Background

This will have two benefits:

• Overnight test will not build everything from scratch all the time (cache key of bst master is different from bst-1.2) (there is already a separate test for testing overnigth jobs without cache)
• There will be a place to test a remote cache server works with buildstream

Task description

• Setup cache server using the one included in buildstream (see BuildStream/infrastructure/infrastructure!1 (merged))
  • Supports master
  • Supports bst-1 branch
• Change CI to point to it (see !2004 (merged))

Acceptance Criteria

Overnight tests use the new cache server