feat(cli): Add plugin:publish and plugin:add commands support (#10938)

RESOLVES FRMW-2864
RESOLVES FRMW-2868

**What**
Add support for the following cli commands:
- `plugin:publish`
- `plugin:add`

packages/medusa/src/commands/plugin/add.ts

@@ -0,0 +1,17 @@
+import * as yalc from "yalc"
+
+/**
+ * Add the specified plugins to the project from the local packages registry
+ */
+export default async function localAddPlugin({
+  directory,
+  plugin_names,
+}: {
+  directory: string
+  plugin_names: string[]
+}) {
+  await yalc.addPackages(plugin_names, {
+    workingDir: directory,
+    replace: true,
+  })
+}

packages/medusa/src/commands/plugin/publish.ts

@@ -0,0 +1,17 @@
+import * as yalc from "yalc"
+
+/**
+ * Publish the plugin to the local packages registry
+ */
+export default async function localPublishPlugin({
+  directory,
+}: {
+  directory: string
+}) {
+  await yalc.publishPackage({
+    push: true,
+    workingDir: directory,
+    changed: true,
+    replace: true,
+  })
+}