Continue moving the cursor for (half) page scrolling

[antoyo]

Hi.
Not sure if it is the same as #750, so feel free to close if it is the same.

Describe your feature request

I'd like C-u, C-d, C-b, C-f in normal mode to behave the same as in vim (edit: actually, C-b does not have this behavior in vim), that is, even if you see the start/end of the document, those shortcuts continue to move the cursor up/down until the very first/last time.
Helix instead will stop moving the cursor when you see the start/end of the buffer.

[pascalkuthe]

Pretty sure this was a duplicate of #750/#7639 and addressed by #8015