Problem:
After 55ceb31,  z= and tselect don't work if `vim.ui.select` is an async
provider (especially terminal buffers).

Solution:
Drop the `vim.wait()` approach, use an async approach.

fix #39506

Problem:
followup to 55ceb314ca96 #39478
`:oldfiles` and swapfile `:recover` do not delegate to `vim.ui.select`.

Solution:
- Delegate to `vim.ui.select`.
- Fix a long-standing `recover_names` bug where `concat_fnames(dir_name,
  files[i], true)` produced malformed `<dir>//<dir>/<file>` paths (also
  fixes `swapfilelist()`).

Problem:
`:tselect` and `z=` (spell suggest) have their own bespoke select menus.

Solution:
- Delegate to `vim.ui.select` instead.
- Bonus:
  - `:tselect` gains mouse support. `print_tag_list` didn't suport mouseclick.

This causes some minor regressions, which are not blockers:

- `z=` no longer draws the list right-left if 'rightleft' is set.
  - TODO: can/should `vim.ui.select` / `vim.fn.inputlist()` handle that?
- `:tselect`
  - No "column" headings (`# pri kind tag file`).
  - No highlighting: (HLF_T: tag name, HLF_D: file, HLF_CM: extra fields).
  - TODO: can `vim.ui.select()` support highlighted chunks (`[[text, hl_id], ...]`) ?

fix https://github.com/neovim/neovim/issues/25814
fix https://github.com/neovim/neovim/issues/31987