Add setting for hiding the status_bar.cursor_position_button (#36288)

Release Notes:

- Added an option for the status_bar.cursor_position_button. Setting to
`false` will hide the button. It defaults to `true`.

This builds off the recent work to hide the language selection button
(https://github.com/zed-industries/zed/pull/33977). I tried to follow
that pattern, and to pick a clear name for the option, but any
feedback/change is welcome.

---------

Co-authored-by: zumbalogy <3770982+zumbalogy@users.noreply.github.com>

docs/src/configuring-zed.md

@@ -1284,6 +1284,7 @@ Each option controls displaying of a particular toolbar element. If all elements
 ```json
 "status_bar": {
   "active_language_button": true,
+  "cursor_position_button": true
 },
 ```