extension_host: Add npm:install capability (#35144)

This PR adds a new `npm:install` capability for installing npm packges
in extensions.

Currently all npm packages are allowed.

Release Notes:

- N/A

crates/extension_host/src/wasm_host.rs

@@ -8,8 +8,8 @@ use dap::{DebugRequest, StartDebuggingRequestArgumentsRequest};
 use extension::{
     CodeLabel, Command, Completion, ContextServerConfiguration, DebugAdapterBinary,
     DebugTaskDefinition, DownloadFileCapability, ExtensionCapability, ExtensionHostProxy,
-    KeyValueStoreDelegate, ProcessExecCapability, ProjectDelegate, SlashCommand,
-    SlashCommandArgumentCompletion, SlashCommandOutput, Symbol, WorktreeDelegate,
+    KeyValueStoreDelegate, NpmInstallPackageCapability, ProcessExecCapability, ProjectDelegate,
+    SlashCommand, SlashCommandArgumentCompletion, SlashCommandOutput, Symbol, WorktreeDelegate,
 };
 use fs::{Fs, normalize_path};
 use futures::future::LocalBoxFuture;
@@ -585,6 +585,9 @@ impl WasmHost {
                     host: "*".to_string(),
                     path: vec!["**".to_string()],
                 }),
+                ExtensionCapability::NpmInstallPackage(NpmInstallPackageCapability {
+                    package: "*".to_string(),
+                }),
             ],
             _main_thread_message_task: task,
             main_thread_message_tx: tx,