feat(unstable): add support for npm specifier cli arguments for 'deno cache' (#16141)

This commit adds support for npm specifier in "deno cache" subcommand.

```
$ deno cache --unstable npm:vite npm:chalk https://deno.land/std/http/file_server.ts
```

Besides downloading requested npm package(s), it will also download
necessary code from "std/node/".

1 files changed, 12 insertions, 0 deletions

diff --git a/cli/main.rs b/cli/main.rs
index 2ad5c83c0..358f12b17 100644
--- a/cli/main.rs
+++ b/cli/main.rs
@@ -393,6 +393,18 @@ async fn load_and_type_check(
 
   for file in files {
     let specifier = resolve_url_or_path(file)?;
+
+    // TODO(bartlomieju): in the future (after all relevant deno subcommands
+    // have support for npm: specifiers), it would be good to unify this code
+    // in `ProcState::prepare_module_load`.
+    if let Ok(package_ref) = NpmPackageReference::from_specifier(&specifier) {
+      ps.npm_resolver
+        .add_package_reqs(vec![package_ref.req.clone()])
+        .await?;
+      ps.prepare_node_std_graph().await?;
+      continue;
+    }
+
     ps.prepare_module_load(
       vec![specifier],
       false,