Line numbers short mode (#10354)

Followup to #10327 
It can be enabled with the following setting:

"line_indicator_format": "short"

No release note, as the original change didn't go out to Preview yet.

/cc @bartekpacia @0x2CA

Release Notes:

- N/A

assets/settings/default.json

@@ -626,5 +626,12 @@
   "task": {
     // Whether to show task status indicator in the status bar. Default: true
     "show_status_indicator": true
-  }
+  },
+  // Whether to show full labels in line indicator or short ones
+  //
+  // Values:
+  //   - `short`: "2 s, 15 l, 32 c"
+  //   - `long`: "2 selections, 15 lines, 32 characters"
+  // Default: long
+  "line_indicator_format": "long"
 }