Description
The JsonManifestVersionStrategy requires the manifest.json to be a local file. That is checked with file_exists.

I would like to download a manifest over HTTP from a remote service that exposes assets.

• The case is a set of js libraries (mainly ads & partners related) shared with multiple websites.
• This libraries can be updated anytime in a backward-compatible way. I don't want to deploy a new configuration of my application to get updates.
• Assets are served with very long TTL (or Cache-Control: immutable) to get the best browser performances (i.e. a high score in Google Page Speed).

Example

Existing:

framework:
    assets:
        json_manifest_path: '%kernel.project_dir%/public/build/manifest.json'

Expected:

framework:
    assets:
        json_manifest_url: 'https://cdn.example.com/manifest.json'

Implementation:

• The HttpClient component should be used and injected in the new **VersionStrategy.
• Cache policy can be configured on HttpClient level. Directives like stale-while-revalidate and stale-if-error will be recommended.