When scrolling buffers, skip ones that are located in other windows of the same frame

[xged]

Scrolling threw buffers located in other windows with SPC b n (spacemacs/next-useful-buffer), SPC b p and SPC TAB, which usually are at the top of the buffer list, is tiresome. Skip them or change their position in the buffer list.

[syl20bnr]

#2551 partially resolve this for SPC TAB.

[a13ph]

Applies to microstate as well, I guess? same kind of sifting-through behavior, duplicating already visible buffers doesn't seem sought after (when you want that, you do exactly that, usually)

[github-actions]

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