feat: add LSP30 ERC725Account Backup File standard

[mustafademiray]

This PR:

• Introduces LSP-30 ERC725Account Backup File, a new standard defining a portable JSON format for exporting, backing up, and recovering Universal Profiles across multiple networks.
• Specifies the complete v2 backup schema: account metadata, per-network controller configurations, LSP23 cross-chain deployment data, and secret material (both encrypted and unencrypted variants).
• Includes a comprehensive annotated full-file example, per-section field tables, encryption specification (PBKDF2 + AES-GCM), security considerations, and rationale for key design decisions.