refactor(treesitter): typing for Query, TSQuery, and TSQueryInfo

- `TSQuery`: userdata object for parsed query.

- `vim.treesitter.Query`: renamed from `Query`.
  - Add a new field `lang`.

- `TSQueryInfo`:
  - Move to `vim/treesitter/_meta.lua`, because C code owns it.
  - Correct typing for `patterns`, should be a map from `integer`
    (pattern_id) to `(integer|string)[][]` (list of predicates or
    directives).

- `vim.treesitter.QueryInfo` is added.
  - This currently has the same structure as `TSQueryInfo` (exported
    from C code).
  - Document the fields (see `TSQuery:inspect`).

- Add typing for `vim._ts_parse_query()`.

runtime/lua/vim/treesitter/highlighter.lua

@@ -7,7 +7,7 @@ local ns = api.nvim_create_namespace('treesitter/highlighter')
 ---@alias vim.treesitter.highlighter.Iter fun(end_line: integer|nil): integer, TSNode, TSMetadata
 
 ---@class vim.treesitter.highlighter.Query
----@field private _query Query?
+---@field private _query vim.treesitter.query.Query?
 ---@field private lang string
 ---@field private hl_cache table<integer,integer>
 local TSHighlighterQuery = {}