sweep of infrastructure and CP algorithm updates from master to 21.2

This should hopefully bring 21.2 in line with master.

List of commits swept:

• d8e73fd2 track systematics through the SystematicsSvc
• b2647bf9 switch SysCopyHandle to SysReadHandle when used with Sys*DecorHandle
• c1f27376 SysListDumperAlg, fix clang compilation error: decltype(auto) cannot be combined with other type specifiers
• 79002160 switch to using SysListHandle::systematicsVector() instead of for-each
• 59672b20 fix dictionary warnings in EventLoop CP algorithm jobs
• 0d906745 add AnaAlgorithm::endInputFile()
• d63a10df AsgMessaging: add missing ATH_MSG macro
• 315163bf fix for python3 print command

I also removed some tests that were removed in master already and are no longer needed.

cc @tadej @jburr