fix(tags): Allow non-ascii chars in tags

Fixes #856

Author: kristijanhusak

lua/orgmode/files/elements/search.lua

@@ -339,7 +339,7 @@ end
 ---@return OrgTagMatch?, string
 function TagMatch:parse(input)
   local tag
-  tag, input = parse_pattern(input, '[%w_@#%%]+')
+  tag, input = parse_pattern(input, '[\128-\255%w_%%@#]+')
   if not tag then
     return nil, input
   end

lua/orgmode/utils/init.lua

@@ -245,7 +245,7 @@ end
 function utils.parse_tags_string(tags)
   local parsed_tags = {}
   for _, tag in ipairs(vim.split(tags or '', ':')) do
-    if tag:find('^[%w_%%@#]+$') then
+    if tag:find('^[\128-\255%w_%%@#]+$') then
       table.insert(parsed_tags, tag)
     end
   end