setProgressBar
Sets progress value in progress bar. Valid range is 0, 1.0.
Remove progress bar when progress < 0; Change to indeterminate mode when progress > 1.
On Linux platform, only supports Unity desktop environment, you need to specify the *.desktop file name to desktopName field in package.json. By default, it will assume {app.name}.desktop.
On Windows, a mode can be passed. Accepted values are none, normal, indeterminate, error, and paused. If you call setProgressBar without a mode set (but with a value within the valid range), normal will be assumed.