Add fuzz testing harness for `contracts/runtime-guard-wrapper/src/lib.rs` [Refactor]

[Gbangbolaoluwagbemiga]

Problem Statement

We are bringing in a new wave of contributors! As part of our ongoing efforts to improve the Sanctifier ecosystem, we need help with contracts/runtime-guard-wrapper/src/lib.rs.

Task: Add fuzz testing harness for contracts/runtime-guard-wrapper/src/lib.rs.
Context: Create a fuzz test using cargo fuzz to ensure the contract handles unexpected inputs gracefully.

Acceptance Criteria

• Changes are implemented according to the project's style guide.
• Existing tests pass (make test or cargo test).
• New tests are added if applicable.
• Documentation is updated to reflect the changes.

Difficulty Hint

This is a great issue for anyone looking to get involved in the Soroban Smart Contracts stack of the project. If you have questions, drop a comment below!

Tags: smart-contracts,soroban,help wanted,contrib-wave
File Pointer: contracts/runtime-guard-wrapper/src/lib.rs