feat(lsp): vim.lsp.buf.format() supports textDocument/rangesFormatting #27323

While this relies on a proposed LSP 3.18 feature, it's fully backwards
compatible, so IMO there's no harm in adding this already.

Looks like some servers already support for this e.g.
- gopls: https://go-review.googlesource.com/c/tools/+/510235
- clangd: https://github.com/llvm/llvm-project/pull/80180

Fixes #27293

runtime/lua/vim/lsp/protocol.lua

@@ -425,6 +425,7 @@ function protocol.make_client_capabilities()
       },
       rangeFormatting = {
         dynamicRegistration = true,
+        rangesSupport = true,
       },
       completion = {
         dynamicRegistration = false,