Stop extensions' servers and message loops before removing their files (#34208)

Fixes an issue that caused Windows to fail when removing extension's
directories, as Zed had never stop any related processes.

Now:

* Zed shuts down and waits until the end when the language servers are
shut down

* Adds `impl Drop for WasmExtension` where does
`self.tx.close_channel();` to stop a receiver loop that holds the "lock"
on the extension's work dir.
The extension was dropped, but the channel was not closed for some
reason.

* Does more unregistration to ensure `Arc<WasmExtension>` with the `tx`
does not leak further

* Tidies up the related errors which had never reported a problematic
path before

Release Notes:

- N/A

---------

Co-authored-by: Smit Barmase <heysmitbarmase@gmail.com>
Co-authored-by: Smit <smit@zed.dev>

crates/zed/src/main.rs

@@ -441,11 +441,31 @@ pub fn main() {
 
         debug_adapter_extension::init(extension_host_proxy.clone(), cx);
         language::init(cx);
-        language_extension::init(extension_host_proxy.clone(), languages.clone());
         languages::init(languages.clone(), node_runtime.clone(), cx);
         let user_store = cx.new(|cx| UserStore::new(client.clone(), cx));
         let workspace_store = cx.new(|cx| WorkspaceStore::new(client.clone(), cx));
 
+        language_extension::init(
+            language_extension::LspAccess::ViaWorkspaces({
+                let workspace_store = workspace_store.clone();
+                Arc::new(move |cx: &mut App| {
+                    workspace_store.update(cx, |workspace_store, cx| {
+                        workspace_store
+                            .workspaces()
+                            .iter()
+                            .map(|workspace| {
+                                workspace.update(cx, |workspace, _, cx| {
+                                    workspace.project().read(cx).lsp_store()
+                                })
+                            })
+                            .collect()
+                    })
+                })
+            }),
+            extension_host_proxy.clone(),
+            languages.clone(),
+        );
+
         Client::set_global(client.clone(), cx);
 
         zed::init(cx);