feat: introduce forc-pkg level cache

[kayagokalp]

Description

This pull request introduces a persistent CompilationCache to manage engines and compilation state across multiple sessions, enhancing the efficiency and modularity of the forc-pkg package. The changes primarily focus on integrating this cache into the build and check functions, refactoring their logic to utilize the cache, and ensuring thread-safe operations using Mutex. Below are the most important changes grouped by theme:

Introduction of CompilationCache:

• Added CompilationCache struct: A new struct was introduced to hold engines and compilation state using Arc<Mutex<Engines>>. It includes methods for managing engines, clearing programs/modules, setting observers, and executing functions with locked engines. (forc-pkg/src/pkg.rs)

Refactoring build Function:

• Introduced build_with_cache: A new function was added to perform package builds using the CompilationCache, replacing direct usage of Engines with cache-based operations. (forc-pkg/src/pkg.rs)
• Replaced Engines with CompilationCache: Updated the logic in the build function to use the cache for operations like setting observers, accessing engines, and managing compilation state. (forc-pkg/src/pkg.rs) [1] [2] [3]

Refactoring check Function:

• Introduced check_with_cache: Similar to build_with_cache, this function uses the CompilationCache for checking packages, enabling persistent state management during checks. (forc-pkg/src/pkg.rs)
• Integrated cache into check logic: Updated check to use the cache for operations such as dependency namespace creation and AST compilation. (forc-pkg/src/pkg.rs) [1] [2]

Thread-Safety Enhancements:

• Ensured thread-safe engine access: Replaced direct Engines usage with Mutex locks to ensure safe concurrent access to engines in both build and check functions. (forc-pkg/src/pkg.rs) [1] [2] [3]

These changes improve the modularity, maintainability, and efficiency of the forc-pkg package by introducing a persistent cache and ensuring thread-safe operations.