add termux-notification progress bar element

Feature description

The Android documentation for creating notifications includes a convenience method (ie. setProgress(...)) for displaying & updating either a determinate or indeterminate progress bar (see link):

https://developer.android.com/develop/ui/views/notifications/build-notification#progressbar

It would be great to have the termux-notification API/command allow scriptable access to that feature via a command flag/parameter.

(if it's already possible to achieve this w/ the existing flags/parameters of termux-notification , would greatly appreciate an example).

Reference implementation
See link referenced above for relevant Android API documentation.

Ideally the termux-notification implementation of this feature would simply wrap/pass-thru the relevant arguments to Android's setProgress() method such that a Termux user could update the progress bar & mark an operation complete in the same way the setProgress() method natively allows.

Thanks!

Start with the termux-notification command and the linked Android notification progress-bar documentation. Determine how the command can expose determinate and indeterminate progress updates; done should allow scripts to update progress and mark the notification operation complete.