[BUG] Hide leading space when hiding keyword

[Tor Kringeland]

`org-hidden-keywords' was introduced in Org 9.5 and allows hiding
keywords like "#+title:" at the beginning of the buffer.  However if you
have something like

  #+title: A nice title

" A nice title" is displayed at the beginning.  AFAIK it's common to
have a space after "#+title: " in Org files (at least I do it in all my
files).  It'd be nice to have an option to remove display of this space
for keywords included in `org-hidden-keywords'.  (Correct me if there's
a way to do this already.)