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>

extensions/uiua/Cargo.toml

@@ -8,9 +8,9 @@ license = "Apache-2.0"
 [lints]
 workspace = true
 
-[dependencies]
-zed_extension_api = { path = "../../crates/extension_api" }
-
 [lib]
 path = "src/uiua.rs"
 crate-type = ["cdylib"]
+
+[dependencies]
+zed_extension_api = "0.0.4"