feat: refactor dart and elixir LSPs according to the new structure

modules/languages/dart/dart.nix

@@ -0,0 +1,90 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+with lib;
+with builtins; let
+  cfg = config.vim.languages.dart;
+  defaultServer = "dart";
+  servers = {
+    dart = {
+      package = pkgs.dart;
+      lspConfig = ''
+        lspconfig.dart.setup{
+          capabilities = capabilities;
+          on_attach=default_on_attach;
+          cmd = {"${pkgs.dart}/bin/dart"};
+          ${optionalString (cfg.lsp.opts != null) "init_options = ${cfg.lsp.dartOpts}"}
+        }
+      '';
+    };
+  };
+in {
+  options.vim.languages.dart = {
+    enable = mkEnableOption "Dart language support";
+
+    treesitter = {
+      enable = mkOption {
+        description = "Enable Dart treesitter";
+        type = types.bool;
+        default = config.vim.languages.enableTreesitter;
+      };
+      package = nvim.types.mkGrammarOption pkgs "dart";
+    };
+
+    lsp = {
+      enable = mkOption {
+        description = "Enable Dart LSP support";
+        type = types.bool;
+        default = config.vim.languages.enableLSP;
+      };
+      server = mkOption {
+        description = "The Dart LSP server to use";
+        type = with types; enum (attrNames servers);
+        default = defaultServer;
+      };
+      package = mkOption {
+        description = "Dart LSP server package";
+        type = types.package;
+        default = servers.${cfg.lsp.server}.package;
+      };
+      opts = mkOption {
+        description = "Options to pass to Dart LSP server";
+        type = with types; nullOr str;
+        default = null;
+      };
+    };
+
+    flutter-tools = {
+      enable = mkEnableOption "Enable flutter-tools for flutter support";
+
+      color = {
+        enable = mkEnableOption "Whether or mot to highlight color variables at all";
+
+        highlightBackground = mkOption {
+          type = types.bool;
+          default = false;
+          description = "Highlight the background";
+        };
+
+        highlightForeground = mkOption {
+          type = types.bool;
+          default = false;
+          description = "Highlight the foreground";
+        };
+
+        virtualText = {
+          enable = mkEnableOption "Show the highlight using virtual text";
+
+          character = mkOption {
+            type = types.str;
+            default = "■";
+            description = "Virtual text character to highlight";
+          };
+        };
+      };
+    };
+  };
+}