Support downloading packages directly to the remote machines

The MR adds a new task for downloading packages directly to VMs using get_url.

Note regarding using gitlab_deb_host_path accept a local path url (e.g. file:///tmp/file.txt):

• When using get_url with file URI as url Ansible tries to find the file on the machine it's running on and not on the local machine. So left Copy GitLab deb package and gitlab_deb_host_path for the case when user wants to upload deb package from the localhost.

Changes:

• New gitlab_deb_download_url variable to set URL for the GitLab Debian package
• New gitlab_deb_download_url_headers variable in case Debian file is in the private GitLab project as seen in https://gitlab.com/gitlab-org/quality/gitlab-environment-toolkit/-/issues/105#note_583849351
• Changed gitlab_deb_target_path to generate a static name as it will be used for both gitlab_deb_download_url and gitlab_deb_host_path
• Updated docs with the new deb url method

Verified the change against test 1k environment in Distribution QA GCP project.

Closes #105 (closed)