meson: create /var/log/journal/{,remote/} conditionally

Not everybody has those dirs in the filesystem (and they don't need to).
When creating an installation package using $DESTDIR, it is easy enough to
remove or ignore those directories, but if installing into a real root, it
is ugly to create and remove them. Let's add an option so people can skip
it if they want.

Inspired by #12930.

docs/var-log/meson.build

@@ -5,7 +5,7 @@ file = configure_file(
         output : 'README',
         configuration : substs)
 
-if conf.get('HAVE_SYSV_COMPAT') == 1
+if conf.get('HAVE_SYSV_COMPAT') == 1 and get_option('create-log-dirs')
         install_data(file,
                      install_dir : varlogdir)
 endif