* Added missing timeouts to uploads.
Since much of the BackendManager is replicated into the BackendUploader, this code needs to be updated as well.
* Fixed namespace issue
* Fixed issues with timeout in msgraph
Fixed a place where the cancellation token was not applied.
Fixed a problem with msgraph not sending correct DNS information.
Fixed a problem with msgraph downloading the entire file before streaming it, bypassing throttle and tripping the timeout.
Added `ITimeoutExemptBackend` to selectively disable timeouts for backends that do not support it.
Updated the backendmanager to support `ITimeoutExemptBackend`.
Updated the backendmanager to abort as soon as a timeout happens.
* Updated BackendTester to use the `TimeoutObservingStream` and support the `--read-write-timeout` setting.
Updated backend tester code to use `var`
* Fixed a bug reading the `read-write-timeout`
* Updated to using constants with names instead of `-1`.
* 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
The option has no effect.
This closes#3566
The block cache was added originally to work around perceived slow hash table lookups in the database.
By having an in-memory dictionary, lookups would be much faster.
It has no effect on disk wear, as the lookups are read-only.
The impact of such a cache was measured to be minimal with recent versions of SQLite.