feat(oxlint/oxfmt): adopt and fully integrate the recommended language servers

[FLchs]

Hello,

The goal of this PR is to replace oxc_language_server with the two “new” language servers provided by oxlint and oxfmt, as recommended in:
oxc-project/oxc#15119

The motivation is to align with the upstream architecture and rely on the officially recommended entry points instead of using oxc_language_server directly.

Change in architecture:
oxc_language_server should accept different tools
oxlint --lsp and oxfmt --lsp uses oxc_language_server with only the required tool
IDE is calling oxlint --lsp and oxfmt --lsp
oxc_language_server should be generic to support other tools too (vitest, ...)

In addition to the language server changes, this PR:

• Enables formatting through vim.lsp.buf.format in oxfmt
• Adds an :LspOxlintFixAll command to apply automatic fixes, following the official documentation:
  https://oxc.rs/docs/guide/usage/linter/automatic-fixes.html
  -- Adds default configuration (commented) for Oxlint LS

I am currently using this configuration in my own projects, and it has been working very well so far.

This PR updates the oxlint configuration and adds oxfmt support in a single change. I grouped them together because the split of oxc_language_server made it feel more logical to handle both at once. However, I am happy to split this into two separate PRs if that is preferred.

[FLchs]

Thanks to recent updates, specifying a workspaceUri in the init_options is not mandatory anymore.

Customizing the LS settings can now simply be done.
For example, to enable all fixes applied with LspOxlintFixAll'

vim.lsp.config("oxlint", {
	init_options = {
		settings = {
			["fixKind"] = "all",
		},
	},
})

[raviqqe]

Isn't this markdown.mdx? At least, my local Neovim v0.12.0-dev-1977+gdd6ed20272 shows it in the status bar.

[FLchs]

Mhh pretty sure it depends on configuration, with v0.11.5 vanilla I don't get any filetype on mdx files. Not sure about how to manage this case.