fix(tags): Do not sort tags in tags change prompt

Fixes #866

Author: kristijanhusak

lua/orgmode/org/mappings.lua

@@ -43,7 +43,8 @@ end
 ---@param tags? string|string[]
 function OrgMappings:set_tags(tags)
   local headline = self.files:get_closest_headline()
-  local current_tags = utils.tags_to_string(headline:get_own_tags())
+  local headline_tags = headline:get_own_tags()
+  local current_tags = utils.tags_to_string(headline_tags)
 
   if not tags then
     tags = utils.input('Tags: ', current_tags, function(arg_lead)

lua/orgmode/utils/init.lua

@@ -254,11 +254,13 @@ end
 
 function utils.tags_to_string(taglist, sorted)
   local tags = ''
+  local tags_list = taglist
   if #taglist > 0 then
     if sorted then
-      table.sort(taglist)
+      tags_list = vim.deepcopy(taglist)
+      table.sort(tags_list)
     end
-    tags = ':' .. table.concat(taglist, ':') .. ':'
+    tags = ':' .. table.concat(tags_list, ':') .. ':'
   end
   return tags
 end