FUTURE: `deno install` changes (#23498)

This PR implements the changes we plan to make to `deno install` in deno
2.0.
- `deno install` without arguments caches dependencies from
`package.json` / `deno.json` and sets up the `node_modules` folder
- `deno install <pkg>` adds the package to the config file (either
`package.json` or `deno.json`), i.e. it aliases `deno add`
- `deno add` can also add deps to `package.json` (this is gated behind
`DENO_FUTURE` due to uncertainty around handling projects with both
`deno.json` and `package.json`)
- `deno install -g <bin>` installs a package as a globally available
binary (the same as `deno install <bin>` in 1.0)

---------

Co-authored-by: Nathan Whitaker <nathan@deno.com>

1 files changed, 17 insertions, 0 deletions

diff --git a/tests/specs/install/future_install_node_modules/__test__.jsonc b/tests/specs/install/future_install_node_modules/__test__.jsonc
new file mode 100644
index 000000000..eb780d962
--- /dev/null
+++ b/tests/specs/install/future_install_node_modules/__test__.jsonc
@@ -0,0 +1,17 @@
+{
+  "tempDir": true,
+  "envs": {
+    "DENO_FUTURE": "1"
+  },
+  "steps": [
+    {
+      "args": "install",
+      "output": "install.out"
+    },
+    {
+      // ensure deps are actually cached
+      "args": "run --cached-only main.js",
+      "output": ""
+    }
+  ]
+}