* Rewrite the backend manager.
This creates a new more logic backend manager that handles all backend operations.
For each top-level operation, there is now a single backend manager instance that is passed to sub-commands.
The internals of the backend manager are now rewritten to use async logic instead of threading.
The design uses a single task runner that dispatches operations and honors concurrent settings and limits from one place.
The logic for each operation has been moved into a separate files/classes to make it easier to understand each operation.
This fixes#5804
* Fixed a few issues with not awaiting tasks
* Fixed not creating empty databases
* Fixed an issue with hashes not being recorded on download
* Reworked the download logic to avoid attempting to decrypt the file if it has been modified.
* Review fixes
* Renamed db collector to better reflect the purpose.
* Review fixes
* Simplified task control by having all logic in a single class and using async control mechanism
* Fixed the tests
* Made the marking of a backup partial explicitly communicated if the enumeration process is stopped.
* Added support for pausing active transfers
* Introduced transfer token to abort operations.
* Updated the way LiveControl is emitting events.
* Retains the paused state of the server across reboots, this fixes#5760.
* Reworked the way throttle speeds are propagated through LiveControls.
* Added option to pause transfers in the UI.
* Removed throttle settings from the LiveControls class so it is exclusively handled by the ApplicationSettings.
* Removed `thread-priority` as it does not work at all when tasks are used.
* Fixed the stop dialog and API to only support stop and abort.
* Removed unused variables
This fixes a regression introduced around revisions e0899a2a91 ("add
method to add the filelist file") and 3b5af1cf01 ("add method to add
filelist file"), where the filelist was not written by all usages of the
FilesetVolumeWriter. Previously, one would have to invoke
AddFilelistFile with each usage. Now, we simply do so when the
FilesetVolumeWriter is closed.
We also modified the UploadSyntheticFilelist so that the usage of the
FilesetVolumeWriter is contained in a using statement, which will ensure
that it is disposed.
This fixes issue #3924.
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