[Navigation Block] Add option to use the "responsive menu" at all times

[kjellr]

Sometimes a site may want to hide menu items behind a hamburger even on large screens. When "Enable responsive menu" is active, we should add an additional checkbox that lets users enforce that behavior.

Example:

I was sure there was another issue for this, but I couldn't find one. Feel free to close if I'm mistaken!

[karmatosed]

Oh my goodness yes +1 and so many +1's! I actually found myself this week thinking about how to do this in the code so would love this feature, thank you @kjellr for creating the issue 🙌🏻

[jasmussen]

Partially tracked in #30370, but I've turned that one into an overview issue, because this feels small enough that it's worth splitting out anyway and fixing.

[jasmussen]

CC: @vcanales, happy to pair on this one.

[carolinan]

so many +++ :)