Problem:
1. The `Fixedgq()` function is broken (see vim/vim#17412)
2. The `'formatexpr'` for Typescript is not documented, which causes
confusion to users when they try to set `'formatprg'`, since
`'formatexpr'` always takes precedence over `'formatprg'`. See also
https://github.com/HerringtonDarkholme/yats.vim/issues/209
3. Typescript already has a very good and popular formatter called
`prettier`, that can be easily integrated to Vim via `'formatprg'`
(see vim/vim#16989). I don't think there are any good reasons to reinvent a
half-baked version in Vim.
Solution: Remove the Fixedgq() 'formatexpr' function.
fixes: vim/vim#17412closes: vim/vim#17452eb59129d2c
