Various performance and memory optimizations

[jpsamaroo]

This PR implements a variety of performance tweaks and memory usage optimizations to improve the overall performance of Dagger under various conditions, particularly when dealing with many small tasks.

Todo:

• [ ] Remove unnecessary reusable data structures
• [x] Ensure that all reusable objects are cleared on error
• [ ] Implement full test suite for reusable utilities
• [x] Fix warnings
• [ ] Final review