[UX] Views UI: Modal dialogs: Indent form elements that are hidden/shown via #states

[klonos]

Description and screenshots coming up...

This is related to #1828

[klonos]

So, here's the thing... take for example the title field dialog from a view:

[klonos]

...once you check these options, you get this:

[klonos]

[klonos]

...now, you get this:

[klonos]

This is how it should be:

[klonos]

I tried making a start of a PR, but realized that I cannot do much unless we get something like #1969 in place.

[klonos]

...by the way, the above screenshots were made having "hacked" my way through CSS max page height. Here's the really bad UX users get in reality with the modal being in the default 400px height with all these options checked and scrolling required to access/preview them:

[klonos]

So here's what we currently have, compared to how things should ideally look (including #1828):

[klonos]

...what would also help in this specific fieldset would be to rename the "CSS class" labels.

HTML element -> Field HTML element
CSS class -> Field CSS class
CSS class -> Label CSS class
CSS class -> Wrapper CSS class