Add aptly support

* Split aptly support, so all reprepro implementation is kept untouched.

* Added configuration dictionary (similar to current reprepro config) to
  specify the projects/repositories handled by aptly.
  Example configuration:

  our $aptlyrepository  = {
    "apertis:v2022:target" => {
      "default" => {
        "prefix" => "shared/apertis/public",
        "distribution" => "v2022",
        "component" => "target"
      },
      "rebuild" => {
        "prefix" => "shared/apertis/internal",
        "distribution" => "v2022",
        "component" => "target"
      },
    },
    "apertis:v2022:development" => {
      "default" => {
        "prefix" => "shared/apertis/public",
        "distribution" => "v2022",
        "component" => "development"
      },
      "rebuild" => {
        "prefix" => "shared/apertis/internal",
        "distribution" => "v2022",
        "component" => "development"
      },
    },
  };

Signed-off-by: Ariel D'Alessandro <ariel.dalessandro@collabora.com>