I have added an MR (Not sure when we create MR in this new workflow, more of ...

I have added an MR (Not sure when we create MR in this new workflow, more of a patch person) with a very basic implementation of connection with the Package Manager and also included work/suggestions by @grasmash. It will still require considerable work to take this to the finish line. Looking for suggestions/feedback regarding a few items:

1. I have added this change in the .info.yml file as that's how the Automatic Update module was indicating dependency on Package Manager. But as of now, the Package manager is still isn't part of the core and the user will have to clone 8.x-2.x in local to test the working of this MR.

2. When hitting the download button in the Svelte app, the following issues still have to be addressed:

• The Drupal controller doesn't receive value for the project machine name in the request. Some debugging is required in the Svelte code for
  this.
• If the download fails for any reason, the very next time user hits the download button, the system gives the following error 'The staging directory already exists at "/tmp/.package_manager..........'. Will have to check with the Automatic Updates team regarding this.
• Package manager is throwing a 504 error whenever an installation is requested. This can happen for any system. Not sure what's the plan in that case.
• Svelte app isn't showing any loading throbbed after hitting the download button and would also require CSS changes once we have finalized where the download button would be.