Added environment variable for cf-remote path

[victormlg]

Ticket: CFE-4468

[olehermanse]

~ means the user's home folder, we don't want that, we want them to be able to specify a path anywhere on the file system.

Suggested change

	cf_remote_dir = ".cfengine" if "CF_REMOTE_DIR" not in os.environ else os.environ["CF_REMOTE_DIR"]
	return path_append("~/{}/".format(cf_remote_dir), subdir)
	override_dir = os.getenv("CF_REMOTE_DIR")
	if override_dir:
	parent = os.path.dirname(override_dir)
	if not os.path.exists(parent):
	user_error(f"'{parent}' does not exist")
	return path_append(override_dir, subdir)
	return path_append("~/.cfengine/", subdir)