fix: adapt to breaking change on master (#90)

This is a stop-gap fix to avoid errors on latest master after neovim/neovim#19931

This at least gives useful information (the capture name, albeit without leading @), but a full rewrite is needed once nvim-treesitter decides on how to handle the upstream changes to highlight group names.

lua/nvim-treesitter-playground/utils.lua

@@ -65,7 +65,7 @@ function M.get_hl_groups_at_position(bufnr, row, col)
       if hl and ts_utils.is_in_node_range(node, row, col) then
         local c = query._query.captures[capture] -- name of the capture in the query
         if c ~= nil then
-          local general_hl, is_vim_hl = query:_get_hl_from_capture(capture)
+          local general_hl, is_vim_hl = c, false
           local local_hl = not is_vim_hl and (tree:lang() .. general_hl)
           table.insert(
             matches,