patch 9.0.1753: can't move to last non-blank char

Problem: can't move to last non-blank char
Solution: Make g<end> behave like that

Make it possible to move to last non-blank char on a line

We can distinguish between g0 and g^ to move to the very first character
and the first non-blank char.

And while we can move to the last screen char, we cannot go to the last
non-blank screen char.

Since I think g$ is the more widely used and known movement command (and
g<end> is synonymous to it) change the behaviour of g<end> to move to
last non-screen char instead and don't have this be the same command as
the g$ command anymore.

If you want to keep the old behaviour, you can use:

```
nnoremap g<end> g$
```

Add a test to verify the behaviour.

closes: #12593

Signed-off-by: Christian Brabandt <cb@256bit.org>

runtime/doc/motion.txt

@@ -242,8 +242,8 @@ gM			Like "g0", but to halfway the text of the line.
 			Thus "10gM" is near the start of the text and "90gM"
 			is near the end of the text.
 
-							*g$* *g<End>*
-g$ or g<End>		When lines wrap ('wrap' on): To the last character of
+							*g$*
+g$			When lines wrap ('wrap' on): To the last character of
 			the screen line and [count - 1] screen lines downward
 			|inclusive|.  Differs from "$" when a line is wider
 			than the screen.
@@ -255,6 +255,9 @@ g$ or g<End>		When lines wrap ('wrap' on): To the last character of
 			instead of going to the end of the line.
 			When 'virtualedit' is enabled moves to the end of the
 			screen line.
+							*g<End>*
+g<End>			Like |g$| but to the last non-blank character
+			instead of the last character.
 
 							*bar*
 |			To screen column [count] in the current line.