patch 9.1.1634: Clipboard code can be improved

Problem:  Clipboard code can be improved
Solution: Slightly refactor code (Foxe Chen).

This commit does the following:
-  Use garray_T when receiving data instead of manually reallocing
-  formatting fixes
-  skip Wayland test that requires clientserver if x11 not compiled
-  Make some functions static

closes: #17999

Signed-off-by: Foxe Chen <chen.foxe@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

src/version.c

@@ -719,6 +719,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1634,
 /**/
     1633,
 /**/