Drop support for ansible-galaxy and move fully/only to git submodule

.gitmodules

extensions/git/pre-commit

extensions/git/pre-commit

extensions/git/pre-commit.sh

extensions/setup/ansiblegalaxygitsubmodule.py

extensions/setup/required_packages_deb.txt

extensions/setup/required_pip_packages_deb.txt

extensions/setup/role_update.sh

extensions/setup/setup.sh

roles/external/Stouts.sudo

roles/external/ansible-hostname

roles/external/ansible-locale

roles/external/ansible-prerequirements

roles/external/ansible-role-pacman

roles/external/openssh

roles/roles_requirements.yml