Implement a redesigned Mautic Marketplace

This has been discussed in the forums at https://forum.mautic.org/t/mautic-marketplace/12108.

The marketplace is using Packagist API(External link) which is very limited. We cannot filter for example packages that have requirements on Mautic 5. We could get the list of the packages and filter in the UI, but in the list view we get only limited information(External link) and the required libraries are missing.

So instead we've created the Allow List(External link) where we manually set the minimal Mautic version for each package. But that's tedious and so not many packages are listed in the Marketplace.

Another issue is that we need to support at least 2 types of packages:

1. mautic-plugin

2. mautic-theme

Because both types are installable via Marketplace. But Packagist API does not allow us to get both in 1 request. If we try use 2 requests then we get twice as many packages than the user requested by the pagination settings. So if the user wants 10 packages per page, they get 20. And what to do in the next page?

Another issue is that the API doesn't allow us to sort by any parameter.

In summary, we cannot build a good package listing using just the Packagist API.

This project will see us creating a middleware layer through which we can add more functionality, allowing us to incorporate functionality like reviews, ratings, and also extending the marketplace from just using plugins to allowing us to provide themes and campaign packages through the same interface.