Refactor: Organize Ansible project structure

- Reorganized Ansible project structure to follow best practices.
- Created dedicated directories: , , , , and .
- Categorized playbooks into  (host-specific) and  (service-specific).
- Moved all roles into the  directory and standardized their naming conventions.
- Relocated  to  for better variable management.
- Renamed  to  to reflect its global variable scope.
- Created  to correctly set the  to the new  directory.
- Moved  and  into the  directory.
- Added  to  providing explanations for common commands.
- Cleaned up  directories from all individual roles to centralize version control.

roles/mariadb/tests/inventory

@@ -0,0 +1,2 @@
+localhost
+