Add visual end location utility function

Closes #44

lua/ts_context_commentstring/utils.lua

@@ -75,7 +75,7 @@ function M.get_cursor_line_non_whitespace_col_location()
   }
 end
 
----Get the location of the visual section start.
+---Get the location of the visual selection start.
 ---
 ---@return ts_context_commentstring.Location
 function M.get_visual_start_location()
@@ -87,6 +87,16 @@ function M.get_visual_start_location()
   }
 end
 
+---Get the location of the visual selection end.
+---
+---@return ts_context_commentstring.Location
+function M.get_visual_end_location()
+  return {
+    vim.fn.getpos("'>")[2] - 1,
+    vim.fn.getpos("'>")[3] - 1,
+  }
+end
+
 ---Get the node that is on the given location (default first non-whitespace
 ---character of the cursor line). This also handles injected languages via
 ---language tree.