Followup improvements to LSP (#11430)

Addressing things brought up in https://github.com/neovim/neovim/issues/11389 and beyond.

- Bugfix for empty dictionary serialization.
- Reduce markdown previews of code.
- Refactor method triggers to `lsp.buf.*` methods
- Switch to v:lua and get rid of vim interface.
- Get rid of filetype config in favor of something from https://github.com/neovim/nvim-lsp
- Switch error messages to something which doesn't require `ENTER` because if an LSP goes crazy, it'll block neovim.
- Rename `builtin_callbacks` to `default_callbacks`
- Resolve callback at time of calling using default_callbacks instead of at client creation
- Make hover/signatureHelp preview focusable so you can mess with it.
- Add vim.lsp.util.set_qflist and vim.lsp.util.set_loclist and vim.lsp.util.locations_to_items().
- Add apply_textedit and tests which enables a new class of features.
- Fix column offsets in character and bytes in vim.lsp.buf to be correct.

New methods:
- Add textDocument/references under vim.lsp.buf.references()
- Finish textDocument/rename
- Finish textDocument/rangeFormatting and textDocument/format

1 files changed, 6 insertions, 1 deletions

diff --git a/runtime/lua/vim/uri.lua b/runtime/lua/vim/uri.lua
index 0a6e0fcb97..1065f84f4c 100644
--- a/runtime/lua/vim/uri.lua
+++ b/runtime/lua/vim/uri.lua
@@ -77,13 +77,18 @@ local function uri_to_fname(uri)
   else
     uri = uri:gsub('^file://', '')
   end
-
   return uri_decode(uri)
 end
 
+-- Return or create a buffer for a uri.
+local function uri_to_bufnr(uri)
+  return vim.fn.bufadd((uri_to_fname(uri)))
+end
+
 return {
   uri_from_fname = uri_from_fname,
   uri_from_bufnr = uri_from_bufnr,
   uri_to_fname = uri_to_fname,
+  uri_to_bufnr = uri_to_bufnr,
 }
 -- vim:sw=2 ts=2 et