Refactor: vault_password is an inventory parameter

Use inventory.vault_password instead of passing it through every function.

	modified:   ../../lib/ansible/inventory/__init__.py
	modified:   ../../lib/ansible/inventory/vars_plugins/noop.py
	modified:   ../../lib/ansible/playbook/__init__.py
	modified:   ../../lib/ansible/playbook/play.py
	modified:   ../../lib/ansible/runner/__init__.py
	modified:   ../../lib/ansible/runner/action_plugins/add_host.py
	modified:   ../../lib/ansible/runner/action_plugins/group_by.py
	modified:   ../units/TestPlayVarsFiles.py