Implement command `psdk-plugin`

[AerunDev]

Description

As a developer, I want to use psdk-plugin to manage my PSDK plugins (create, test, update) to simplify maintenance.

Note

We'll remove the plugin command from PSDK (aside the one for loading the plugin) and psdk cli will be responsible of plugin management (including build).
It'll accept both workflow:

• Plugin inside a PSDK project (meaning the resources are expected to be at the root of the project and scripts at the root of the plugin)
• Plugin outside a PSDK project (meaning both resources and scripts are expected to be at the root of the plugin)
  The definition file remain the same for both workflow

Acceptance criteria

• psdk-plugin exposes the same arguments as the original plugin manager.
• The command detects the project or switches to standalone mode.
• A clear message lists available actions (create, delete, update, etc.).