Carousel enhancements

[golinski]

What does this implement/fix? Explain your changes.

This implements changes to the Carousel component proposed in https://github.com/peregrine-cms/enhancements/issues/78:

• Allow aligning caption to left/center/right.
• Allow turning off the translucent overlay over the image (these two setting on the carousel level):
• Some settings can now be set also per slide:

Does this close any currently open issues?

https://github.com/peregrine-cms/enhancements/issues/78

Where has this been tested?

locally

Browser (version): Opera (82.0.4227.33), mostly eqivalent to current Chrome

[reusr1]

did some testing around the new feature, looks good to me