Add Argcomplete for Command-Line Auto-Completion & Completer Functions

[httpdss]

Overview:
This pull request introduces command-line auto-completion for the struct script using the argcomplete library, along with some refactoring and enhancements in the command structure. Additionally, completer functions are implemented to streamline argument handling.

Changes:

• Added argcomplete for auto-completion in the Dockerfile and Python scripts.
• Updated the README.md with instructions for enabling auto-completion.
• Modified YAML template files to use a consistent syntax for variables ({{@ var @}}).
• Integrated command-line completers for options such as log_level and file_strategy in the struct_module.
• Updated the requirements.txt to include argcomplete.
• Created tests for filter functions, focusing on get_latest_release and stringify.

Justification:
The inclusion of command-line auto-completion improves the developer experience by allowing faster and more accurate command entry. The added completers make commands more user-friendly and reduce errors during input. YAML files have been refactored for better consistency.

Impact:

• Users will now benefit from auto-completion when using the struct script.
• The new completion functionality will require reloading of shell configuration for it to take effect.
• Refactored YAML templates and improved testing coverage enhance maintainability and consistency.