Improve setting up header images in Customizer

[Presskopp]

I think the process of setting up header images in Customizer can be more streamlined.

When only 1 image is there (uploaded or suggested), why do we offer the 'randomize' option? If you click the button, it gets the 'selected' class, the preview greys out, but nothing has been changed (how could it having only 1 image) -

1) Shouldn't this button rather be only there if we have more then 1 image?

2) Small glich

Scenario:
Current header image is not set
We have 1 uploaded image
Set it to 'Randomizing uploaded headers'
then delete the image (clicking 'X')
Publish
It's still set to 'randomize headers' instead of 'no image selected'

I think it should switch to 'No image set' in the moment the image is deleted

There was a lot of activity in #21785 I'm unable to sum this all up

[Presskopp]

I forgot to mention:

When in 'Customizing Header Media' you can click at 'Header Video' and description (= Select Video Button), but NOT the field 'No video selected'
you can't click 'Header Image' but 'Current Header' and NOT the field 'No image set' (and NOT 'suggested')

BUT

adding a widget, let's use the image widget here:

I CAN click on the field 'No image selected'

so after all this is not very consistent, don't you think?

[celloexpressions]

This should happen following (or alongside, but preferably not before) #36581. The header image control needs a broad technical and usability modernization.