This PR has a large blast radius because it takes the final step and bumps up the Controller to be fully async.
We have historically done a piece-by-piece update, so all operations were already async but the controller interface was kept synchronous.
With this update, the controller is now fully async and all tests are updated.
Most places where the new C# compiler warns about function names not ending in `Async` were also adressed, giving a massive refactor change.
Functionally, no changes are done.
This ensures that files cannot appear on the remote destination, despite terminating the host program.
This fixes#4485
There is still work needed to handle the repair and compact operations so they use transactions and can commit changes during transfer progress.
Changed a few things on the way, removing the log process
# Conflicts:
# Duplicati/Library/Main/Controller.cs
# Duplicati/Library/Main/Database/ExtensionMethods.cs
# Duplicati/Library/Main/Database/LocalBackupDatabase.cs
# Duplicati/Library/Main/Duplicati.Library.Main.csproj
# Duplicati/Library/Main/Operation/BackupHandler.cs
# Duplicati/Library/Main/Operation/FilelistProcessor.cs
# Duplicati/Library/Main/Operation/PurgeBrokenFilesHandler.cs
# Duplicati/Library/Main/Operation/TestFilterHandler.cs
# Duplicati/Library/Main/Options.cs
# Duplicati/Library/Main/ResultClasses.cs
# Duplicati/UnitTest/BasicSetupHelper.cs
Kenneth Skovhede