patch 9.1.0142: getregion() can be improved

Problem:  getregion() can be improved (after v9.1.120)
Solution: change getregion() implementation to use pos as lists and
          one optional {opt} dictionary (Shougo Matsushita)

Note: The following is a breaking change!

Currently, the getregion() function (included as of patch v9.1.120) takes
3 arguments: the first 2 arguments are strings, describing a position,
arg3 is the type string.

However, that is slightly inflexible, there is no way to specify
additional arguments. So let's instead change the function signature to:

getregion(pos1, pos2 [, {Dict}]) where both pos1 and pos2 are lists.
This is slightly cleaner, and gives us the flexibility to specify
additional arguments as key/value pairs to the optional Dict arg.

Now it supports the "type" key to specify the selection type
(characterwise, blockwise or linewise) and now in addition one can also
define the selection type, independently of what the 'selection' option
actually is.

Technically, this is a breaking change, but since the getregion()
Vimscript function is still quite new, this should be fine.

closes: #14090

Co-authored-by: zeertzjq <zeertzjq@outlook.com>
Signed-off-by: Shougo Matsushita <Shougo.Matsu@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

src/version.c

@@ -704,6 +704,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    142,
 /**/
     141,
 /**/