Problem:
  `vim.lsp.diagnostic.on_diagnostic` accepts an undocumented severity_limit
  option which is widely used.

Solution:
  Deprecate it in favour of `{min = severity}` used in `vim.diagnostic`.
  Since this is undocumented, the schedule for removal is accelerated to
  0.11.

refactor(lsp): move glob parsing to vim.glob

Moving the logic for using vim.lpeg to create a match pattern from a
glob into `vim.glob`. There are several places in the LSP spec that
use globs, and it's very useful to have glob matching as a
generally-available utility.

This is the command invoked repeatedly to make the changes:

    :%s/^\(.*\)|\%(\*\(\d\+\)\)\?$\n\1|\%(\*\(\d\+\)\)\?$/\=submatch(1)..'|*'..(max([str2nr(submatch(2)),1])+max([str2nr(submatch(3)),1]))/g

refactor!: `vim.lsp.inlay_hint()` -> `vim.lsp.inlay_hint.enable()`

Problem:
The LSP specification allows inlay hints to include tooltips, clickable
label parts, and code actions; but Neovim provides no API to query for
these.

Solution:
Add minimal viable extension point from which plugins can query for
inlay hints in a range, in order to build functionality on top of.

Possible Next Steps
---

- Add `virt_text_idx` field to `vim.fn.getmousepos()` return value, for
  usage in mappings of `<LeftMouse>`, `<C-LeftMouse>`, etc

Fixes a regression from 5e5f5174e3faa862a9bc353aa7da41487911140b

Until that commit we had a logic like this:
`local prefix = startbyte and line:sub(startbyte + 1) or line_to_cursor:sub(word_boundary)`

The commit changed the logic and no longer cut off the line at the cursor,  resulting in a prefix that included trailing characters