Fix most llvm-12 clang-tidy warnings in IO code
Results can be seen here https://gitlab.cs.fau.de/aj46ezos/emper/-/jobs/385513.
The IoContext warning is legitim and should be fixed but it is solved by !201.
- Improve future member types
- GlobalIoContext fix type of cqe return type (
s/uint32_t/int32_t/) - Some returns types
- Ignore integer to pointer cast warning
- Fix
SimpleDiskAndNetworkTest
Thanks llvm 12 :)
Edited by Maxim Onciul