The default is to report progress every second.
In some cases the report output is stuck at the "Starting backup..." phase.
This PR adds a new `Starting_Operation` enum to indicate that we do not yet know which operation is starting.
Then an additional trigger is added to flush the progress when the pahse changes. This means that as soon as we know which operation is active, this will be flushed to the UI.
This updates VSS to default use Vanara in favor of AlphaVSS which is no longer maintained.
The build for Vanara requires targeting `net8.0-windows7.0`, which will cause significant build overhead and complexity for cross platform builds.
To counter this, the setup is to have a single project, `Duplicati.Library.WindowsModules`, that is targeting `net8.0-windows7.0`.
The output from this project is then hoisted into the TrayIcon project for Windows builds so the files are available when debugging on Windows.
A top-level dummy executable project is added to ensure the project always builds.
The built modules are then loaded with reflection when requested.
With the use of Vanara there is now also support for using BackupRead to read files without making a VSS snapshot.
With BackupRead, it is possible to read locked files, but it still requires the SeBackupPrivilege as VSS does as well.
Unfortunately, the `vssapi.dll` file is not shipped for Arm64 on Windows, so even with Vanara this will not work, and only WMIC is supported on Arm64.
A workaround is to run Duplicati with x64 emulation if more advanced VSS features are needed (HyperV and MSSQL support).
This PR also updates options and filters out unsupported options for each operating system, so options that are not supported by the current OS are not reported and will give warnings if they are used, as opposed to just being ignored.
The release builder project has been updated to exclude the unused project, and purge unwanted outputs.
This PR removes the default value of `file` as a throttle exempt backend, so all backends are subject to throttle by default.
This change makes the option easier to work with as the empty string could not be used to undo the default value, and fixing this would make the options be applied inconsistently.
Also fixed two errors in the help text for the option.
Kenneth Skovhede