Fix issues with extension API that come up when moving Svelte into an extension (#9611)

We're doing it. Svelte support is moving into an extension. This PR
fixes some issues that came up along the way.

Notes

* extensions need to be able to retrieve the path the `node` binary
installed by Zed
* previously we were silently swallowing any errors that occurred while
loading a grammar
* npm commands ran by extensions weren't run in the right directory
* Tree-sitter's WASM stdlib didn't support a C function (`strncmp`)
needed by the Svelte parser's external scanner
* the way that LSP installation status was reported was unnecessarily
complex

Release Notes:

- Removed built-in support for the Svelte and Gleam languages, because
full support for those languages is now available via extensions. These
extensions will be suggested for download when you open a `.svelte` or
`.gleam` file.

---------

Co-authored-by: Marshall <marshall@zed.dev>

crates/zed/src/main.rs

@@ -47,8 +47,8 @@ use std::{
 };
 use theme::{ActiveTheme, SystemAppearance, ThemeRegistry, ThemeSettings};
 use util::{
-    async_maybe,
     http::{HttpClient, HttpClientWithUrl},
+    maybe,
     paths::{self, CRASHES_DIR, CRASHES_RETIRED_DIR},
     ResultExt, TryFutureExt,
 };
@@ -455,7 +455,7 @@ async fn installation_id() -> Result<(String, bool)> {
 }
 
 async fn restore_or_create_workspace(app_state: Arc<AppState>, cx: AsyncAppContext) {
-    async_maybe!({
+    maybe!(async {
         if let Some(location) = workspace::last_opened_workspace_paths().await {
             cx.update(|cx| {
                 workspace::open_paths(