Progress Bar - use width instead of scaleX to allow rounded progress bar

[jdforsythe]

https://github.com/ionic-team/ionic-framework/blob/e1c0f457966ab79c7a8774ec9bd0b34458067305/core/src/components/progress-bar/progress-bar.tsx#L102

The scaleX() also scales border-radius. If you use border radius on the top-left and bottom-right to make a round tip to the progress bar, it distorts across the width of the progress bar.

Changing to:

<div part="progress" class="progress" style={{ width: `calc(100% * ${finalValue})` }}></div>,

would scale it similarly without scaling the border-radius