feat: cue language server

[edeustua]

This PR adds support for the CUE language (https://github.com/cue-lang/cue) by integrating its official language server protocol implementation (cue lsp).

Background:

• Previously, CUE language support was provided through Dagger's LSP implementation, which has since been discontinued
• CUE is gaining significant adoption, with over 5.2k GitHub stars
• Notable projects like Timoni (https://github.com/stefanprodan/timoni) are embracing CUE for configuration management

This change ensures continued and improved CUE support through the official, maintained language server.

[glepnir]

Suggested change

	local root_files = {
	'cue.mod',
	'.git',
	}
	return {
	default_config = {
	cmd = { 'cue', 'lsp' },
	filetypes = { 'cue' },
	root_dir = function(fname)
	return util.root_pattern(unpack(root_files))(fname)
	end,
	return {
	default_config = {
	cmd = { 'cue', 'lsp' },
	filetypes = { 'cue' },
	root_dir = function(fname)
	return util.root_pattern(unpack({ 'cue.mod', '.git' }))(fname)
	end,