callback on file picker selection

[gregriggins36]

No description provided.

[vinceglb]

Thanks a lot for your PR @gregriggins36! I will probably merge the PR #300 instead that goes beyond:

val multipleFilesPickerWithState = rememberFilePickerLauncher(
    type = FileKitType.Image,
    mode = FileKitMode.MultipleWithState(),
) { result ->
    when (result) {
        FileKitPickerState.Cancelled -> println("File picker cancelled")
        is FileKitPickerState.Started -> println("Started picking ${result.total} files")
        is FileKitPickerState.Progress -> println("New files processed: ${result.processed.size} / ${result.total}")
        is FileKitPickerState.Completed -> println("File picker completed with ${result.result.size} files")
    }
}

Button(onClick = { multipleFilesPickerWithState.launch() }) {
    Text("Picke images with state")
}

and

val files = FileKit.openFilePicker(
    type = FileKitType.Image,
    mode = FileKitMode.MultipleWithState(),
)

files.collect { result ->
    when (result) {
        FileKitPickerState.Cancelled -> println("File picker cancelled")
        is FileKitPickerState.Started -> println("Started picking ${result.total} files")
        is FileKitPickerState.Progress -> println("New files processed: ${result.processed.size} / ${result.total}")
        is FileKitPickerState.Completed -> println("File picker completed with ${result.result.size} files")
    }
}

I'm really interested in having your feedback!