Allow memory.fill and memory.copy in Hooks [DO NOT MERGE]

[tequdev]

High Level Overview of Change

Added a limit to the size of memory pages in guard-checker allows for WASM's memory.fill and memory.copy instructions.

Context of Change

require: #622

Type of Change

• New feature (non-breaking change which adds functionality)
• Tests (you added tests for code that already exists, or your new feature included in this PR)

API Impact

• Public API: New feature (new methods and/or new fields)
• Public API: Breaking change (in general, breaking changes should only impact the next api_version)
• libxrpl change (any change that may affect libxrpl or dependents of libxrpl)
• Peer protocol change (must be backward compatible or bump the peer protocol version)