Implement Global Configuration for Pysertive

[abeltavares]

Description

Introduce a global configuration system to enable or disable contract checks across the entire application. This will facilitate different environments like development, testing, and production.

Suggested Implementation

Create a Config class with attributes to control the enforcement of preconditions, postconditions, and invariants. Update decorators to respect the global configuration settings.

Acceptance Criteria

• Config class is created with appropriate attributes.
• Decorators are updated to respect global configuration settings.
• Unit tests are written to ensure global configuration works as expected.