This moves the throttle support to the StreamUtil throttled stream, which allows multiple streams to share a throttle value, such that the throttle setting is applied to the entire communication from Duplicati, and not for each connection.
This also cleans up a bit in the progress reporting, where the backend manager now keeps track of the "active" transfer and only emits progress on that. Once it finishes, a new transfer is promoted a "active".
* 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
Kenneth Skovhede