Add comparison to BIP-118 in BIP-448

The recent PR submitted for review introduces several crucial enhancements to Bitcoin Improvement Proposals (BIPs). Notably, it addresses the previously missing comparison with Anonymous Proposal Overlay (APO) by including it in the discussion. Additionally, this PR is significant as it integrates delegation mechanisms and optimized Discreet Log Contracts (DLCs), highlighting their potential as foundational components for future soft forks. These additions are aimed at improving the overall framework and functionality, ensuring that the system remains robust and adaptable to new technologies and methodologies in blockchain development.