Is your feature request related to a problem? Please describe.
Import templates from nextcloud in "master slides" of Collabora Online's impress, similar to remote fonts

Describe the solution you'd like

• We are adding a new remote_asset_config.url config in COOL with PR Improve impress templates CollaboraOnline/online#10463. This will work similarly to remote_font_config

• This will be upgrade a from remote_font_config.url which was only designed for fonts but remote_asset_config can take fonts, templates and can also be extended in the future if we want fetch other kind of assets.

• from the richdocuments' side I expect a new endpoint which can serve json which can have both fonts and impress presentation templates.

• json format would be

{
  "kind": "assetconfiguration",
  "server": "remoteserver",
  "templates": {
    "presentation": [
      {
        "uri": "http://localhost:8080/static/impress-template/template1.otp",
        "version": "1"
      },
      {
        "uri": "http://localhost:8080/static/impress-template/template2.otp",
        "version": "2"
      },
      {
        "uri": "http://localhost:8080/static/impress-template/template3.otp",
        "version": "3"
      }
    ]
  },
  "fonts": [
    {
      "uri": "http://localhost:8080/static/font/font1.ttf",
      "version": "1"
    },
    {
      "uri": "http://localhost:8080/static/font/font2.ttf",
      "version": "2"
    },
    {
      "uri": "http://localhost:8080/static/font/font3.ttf",
      "version": "3"
    }
  ]
}

Additional context

• For backward compatibility we have kept remote_font_config.
• I have created RemoteConfigServer for testing